CINXE.COM

<!doctype html><html lang="en-US" prefix="og: https://ogp.me/ns#"><head><meta charSet="utf-8"/><meta name="viewport" content="width=device-width,initial-scale=1"/><link rel="icon" href="https://developer.mozilla.org/favicon-48x48.bc390275e955dacb2e65.png"/><link rel="apple-touch-icon" href="https://developer.mozilla.org/apple-touch-icon.528534bba673c38049c2.png"/><meta name="theme-color" content="#ffffff"/><link rel="manifest" href="https://developer.mozilla.org/manifest.f42880861b394dd4dc9b.json"/><link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="MDN Web Docs"/><title>JSON - JavaScript | MDN</title><link rel="alternate" title="JSON" href="https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="de"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/es/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="es"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="fr"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="ja"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/ko/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="ko"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="pt"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/ru/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="ru"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="zh"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/zh-TW/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="zh-Hant"/><link rel="alternate" title="JSON" href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON" hrefLang="en"/><link rel="preload" as="font" type="font/woff2" href="/static/media/Inter.var.c2fe3cb2b7c746f7966a.woff2" crossorigin=""/><link rel="alternate" type="application/rss+xml" title="MDN Blog RSS Feed" href="https://developer.mozilla.org/en-US/blog/rss.xml" hrefLang="en"/><meta name="description" content="The JSON namespace object contains static methods for parsing values from and converting values to JavaScript Object Notation (JSON)."/><meta property="og:url" content="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON"/><meta property="og:title" content="JSON - JavaScript | MDN"/><meta property="og:type" content="website"/><meta property="og:locale" content="en_US"/><meta property="og:description" content="The JSON namespace object contains static methods for parsing values from and converting values to JavaScript Object Notation (JSON)."/><meta property="og:image" content="https://developer.mozilla.org/mdn-social-share.d893525a4fb5fb1f67a2.png"/><meta property="og:image:type" content="image/png"/><meta property="og:image:height" content="1080"/><meta property="og:image:width" content="1920"/><meta property="og:image:alt" content="The MDN Web Docs logo, featuring a blue accent color, displayed on a solid black background."/><meta property="og:site_name" content="MDN Web Docs"/><meta name="twitter:card" content="summary_large_image"/><meta name="twitter:creator" content="MozDevNet"/><link rel="canonical" href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON"/><style media="print">.article-actions-container,.document-toc-container,.language-menu,.main-menu-toggle,.on-github,.page-footer,.place,.sidebar,.top-banner,.top-navigation-main,ul.prev-next{display:none!important}.main-page-content,.main-page-content pre{padding:2px}.main-page-content pre{border-left-width:2px}</style><script src="/static/js/gtag.js" defer=""></script><script defer="" src="/static/js/main.f565372a.js"></script><link href="/static/css/main.3d9e7a02.css" rel="stylesheet"/></head><body><script>if(document.body.addEventListener("load",(t=>{t.target.classList.contains("interactive")&&t.target.setAttribute("data-readystate","complete")}),{capture:!0}),window&&document.documentElement){const t={light:"#ffffff",dark:"#1b1b1b"};try{const e=window.localStorage.getItem("theme");e&&(document.documentElement.className=e,document.documentElement.style.backgroundColor=t[e]);const o=window.localStorage.getItem("nop");o&&(document.documentElement.dataset.nop=o)}catch(t){console.warn("Unable to read theme from localStorage",t)}}</script><div id="root"><ul id="nav-access" class="a11y-nav"><li><a id="skip-main" href="#content">Skip to main content</a></li><li><a id="skip-search" href="#top-nav-search-input">Skip to search</a></li><li><a id="skip-select-language" href="#languages-switcher-button">Skip to select language</a></li></ul><div class="page-wrapper category-javascript document-page"><div class="top-banner loading"><section class="place top container"></section></div><div class="sticky-header-container"><header class="top-navigation "><div class="container "><div class="top-navigation-wrap"><a href="/en-US/" class="logo" aria-label="MDN homepage"><svg id="mdn-docs-logo" xmlns="http://www.w3.org/2000/svg" x="0" y="0" viewBox="0 0 694.9 104.4" style="enable-background:new 0 0 694.9 104.4" xml:space="preserve" role="img"><title>MDN Web Docs</title><path d="M40.3 0 11.7 92.1H0L28.5 0h11.8zm10.4 0v92.1H40.3V0h10.4zM91 0 62.5 92.1H50.8L79.3 0H91zm10.4 0v92.1H91V0h10.4z" class="logo-m"></path><path d="M627.9 95.6h67v8.8h-67v-8.8z" class="logo-_"></path><path d="M367 42h-4l-10.7 30.8h-5.5l-10.8-26h-.4l-10.5 26h-5.2L308.7 42h-3.8v-5.6H323V42h-6.5l6.8 20.4h.4l10.3-26h4.7l11.2 26h.5l5.7-20.3h-6.2v-5.6H367V42zm34.9 20c-.4 3.2-2 5.9-4.7 8.2-2.8 2.3-6.5 3.4-11.3 3.4-5.4 0-9.7-1.6-13.1-4.7-3.3-3.2-5-7.7-5-13.7 0-5.7 1.6-10.3 4.7-14s7.4-5.5 12.9-5.5c5.1 0 9.1 1.6 11.9 4.7s4.3 6.9 4.3 11.3c0 1.5-.2 3-.5 4.7h-25.6c.3 7.7 4 11.6 10.9 11.6 2.9 0 5.1-.7 6.5-2 1.5-1.4 2.5-3 3-4.9l6 .9zM394 51.3c.2-2.4-.4-4.7-1.8-6.9s-3.8-3.3-7-3.3c-3.1 0-5.3 1-6.9 3-1.5 2-2.5 4.4-2.8 7.2H394zm51 2.4c0 5-1.3 9.5-4 13.7s-6.9 6.2-12.7 6.2c-6 0-10.3-2.2-12.7-6.7-.1.4-.2 1.4-.4 2.9s-.3 2.5-.4 2.9h-7.3c.3-1.7.6-3.5.8-5.3.3-1.8.4-3.7.4-5.5V22.3h-6v-5.6H416v27c1.1-2.2 2.7-4.1 4.7-5.7 2-1.6 4.8-2.4 8.4-2.4 4.6 0 8.4 1.6 11.4 4.7 3 3.2 4.5 7.6 4.5 13.4zm-7.7.6c0-4.2-1-7.4-3-9.5-2-2.2-4.4-3.3-7.4-3.3-3.4 0-6 1.2-8 3.7-1.9 2.4-2.9 5-3 7.7V57c0 3 1 5.6 3 7.7s4.5 3.1 7.6 3.1c3.6 0 6.3-1.3 8.1-3.9 1.8-2.7 2.7-5.9 2.7-9.6zm69.2 18.5h-13.2v-7.2c-1.2 2.2-2.8 4.1-4.9 5.6-2.1 1.6-4.8 2.4-8.3 2.4-4.8 0-8.7-1.6-11.6-4.9-2.9-3.2-4.3-7.7-4.3-13.3 0-5 1.3-9.6 4-13.7 2.6-4.1 6.9-6.2 12.8-6.2 5.7 0 9.8 2.2 12.3 6.5V22.3h-8.6v-5.6h15.8v50.6h6v5.5zM493.2 56v-4.4c-.1-3-1.2-5.5-3.2-7.3s-4.4-2.8-7.2-2.8c-3.6 0-6.3 1.3-8.2 3.9-1.9 2.6-2.8 5.8-2.8 9.6 0 4.1 1 7.3 3 9.5s4.5 3.3 7.4 3.3c3.2 0 5.8-1.3 7.8-3.8 2.1-2.6 3.1-5.3 3.2-8zm53.1-1.4c0 5.6-1.8 10.2-5.3 13.7s-8.2 5.3-13.9 5.3-10.1-1.7-13.4-5.1c-3.3-3.4-5-7.9-5-13.5 0-5.3 1.6-9.9 4.7-13.7 3.2-3.8 7.9-5.7 14.2-5.7s11 1.9 14.1 5.7c3 3.7 4.6 8.1 4.6 13.3zm-7.7-.2c0-4-1-7.2-3-9.5s-4.8-3.5-8.2-3.5c-3.6 0-6.4 1.2-8.3 3.7s-2.9 5.6-2.9 9.5c0 3.7.9 6.8 2.8 9.4 1.9 2.6 4.6 3.9 8.3 3.9 3.6 0 6.4-1.3 8.4-3.8 1.9-2.6 2.9-5.8 2.9-9.7zm45 5.8c-.4 3.2-1.9 6.3-4.4 9.1-2.5 2.9-6.4 4.3-11.8 4.3-5.2 0-9.4-1.6-12.6-4.8-3.2-3.2-4.8-7.7-4.8-13.7 0-5.5 1.6-10.1 4.7-13.9 3.2-3.8 7.6-5.7 13.2-5.7 2.3 0 4.6.3 6.7.8 2.2.5 4.2 1.5 6.2 2.9l1.5 9.5-5.9.7-1.3-6.1c-2.1-1.2-4.5-1.8-7.2-1.8-3.5 0-6.1 1.2-7.7 3.7-1.7 2.5-2.5 5.7-2.5 9.6 0 4.1.9 7.3 2.7 9.5 1.8 2.3 4.4 3.4 7.8 3.4 5.2 0 8.2-2.9 9.2-8.8l6.2 1.3zm34.7 1.9c0 3.6-1.5 6.5-4.6 8.5s-7 3-11.7 3c-5.7 0-10.6-1.2-14.6-3.6l1.2-8.8 5.7.6-.2 4.7c1.1.5 2.3.9 3.6 1.1s2.6.3 3.9.3c2.4 0 4.5-.4 6.5-1.3 1.9-.9 2.9-2.2 2.9-4.1 0-1.8-.8-3.1-2.3-3.8s-3.5-1.3-5.8-1.7-4.6-.9-6.9-1.4c-2.3-.6-4.2-1.6-5.7-2.9-1.6-1.4-2.3-3.5-2.3-6.3 0-4.1 1.5-6.9 4.6-8.5s6.4-2.4 9.9-2.4c2.6 0 5 .3 7.2.9 2.2.6 4.3 1.4 6.1 2.4l.8 8.8-5.8.7-.8-5.7c-2.3-1-4.7-1.6-7.2-1.6-2.1 0-3.7.4-5.1 1.1-1.3.8-2 2-2 3.8 0 1.7.8 2.9 2.3 3.6 1.5.7 3.4 1.2 5.7 1.6 2.2.4 4.5.8 6.7 1.4 2.2.6 4.1 1.6 5.7 3 1.4 1.6 2.2 3.7 2.2 6.6zM197.6 73.2h-17.1v-5.5h3.8V51.9c0-3.7-.7-6.3-2.1-7.9-1.4-1.6-3.3-2.3-5.7-2.3-3.2 0-5.6 1.1-7.2 3.4s-2.4 4.6-2.5 6.9v15.6h6v5.5h-17.1v-5.5h3.8V51.9c0-3.8-.7-6.4-2.1-7.9-1.4-1.5-3.3-2.3-5.6-2.3-3.2 0-5.5 1.1-7.2 3.3-1.6 2.2-2.4 4.5-2.5 6.9v15.8h6.9v5.5h-20.2v-5.5h6V42.4h-6.1v-5.6h13.4v6.4c1.2-2.1 2.7-3.8 4.7-5.2 2-1.3 4.4-2 7.3-2s5.3.7 7.5 2.1c2.2 1.4 3.7 3.5 4.5 6.4 1.1-2.5 2.7-4.5 4.9-6.1s4.8-2.4 7.9-2.4c3.5 0 6.5 1.1 8.9 3.3s3.7 5.6 3.7 10.2v18.2h6.1v5.5zm42.5 0h-13.2V66c-1.2 2.2-2.8 4.1-4.9 5.6-2.1 1.6-4.8 2.4-8.3 2.4-4.8 0-8.7-1.6-11.6-4.9-2.9-3.2-4.3-7.7-4.3-13.3 0-5 1.3-9.6 4-13.7 2.6-4.1 6.9-6.2 12.8-6.2s9.8 2.2 12.3 6.5V22.7h-8.6v-5.6h15.8v50.6h6v5.5zm-13.3-16.8V52c-.1-3-1.2-5.5-3.2-7.3s-4.4-2.8-7.2-2.8c-3.6 0-6.3 1.3-8.2 3.9-1.9 2.6-2.8 5.8-2.8 9.6 0 4.1 1 7.3 3 9.5s4.5 3.3 7.4 3.3c3.2 0 5.8-1.3 7.8-3.8 2.1-2.6 3.1-5.3 3.2-8zm61.5 16.8H269v-5.5h6V51.9c0-3.7-.7-6.3-2.2-7.9-1.4-1.6-3.4-2.3-5.7-2.3-3.1 0-5.6 1-7.4 3s-2.8 4.4-2.9 7v15.9h6v5.5h-19.3v-5.5h6V42.4h-6.2v-5.6h13.6V43c2.6-4.6 6.8-6.9 12.7-6.9 3.6 0 6.7 1.1 9.2 3.3s3.7 5.6 3.7 10.2v18.2h6v5.4h-.2z" class="logo-text"></path></svg></a><button title="Open main menu" type="button" class="button action has-icon main-menu-toggle" aria-haspopup="menu" aria-label="Open main menu" aria-expanded="false"><span class="button-wrap"><span class="icon icon-menu "></span><span class="visually-hidden">Open main menu</span></span></button></div><div class="top-navigation-main"><nav class="main-nav" aria-label="Main menu"><ul class="main-menu nojs"><li class="top-level-entry-container active"><button type="button" id="references-button" class="top-level-entry menu-toggle" aria-controls="references-menu" aria-expanded="false">References</button><a href="/en-US/docs/Web" class="top-level-entry">References</a><ul id="references-menu" class="submenu references hidden inline-submenu-lg" aria-labelledby="references-button"><li class="apis-link-container mobile-only "><a href="/en-US/docs/Web" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Overview / Web Technology</div><p class="submenu-item-description">Web technology reference for developers</p></div></a></li><li class="html-link-container "><a href="/en-US/docs/Web/HTML" class="submenu-item "><div class="submenu-icon html"></div><div class="submenu-content-container"><div class="submenu-item-heading">HTML</div><p class="submenu-item-description">Structure of content on the web</p></div></a></li><li class="css-link-container "><a href="/en-US/docs/Web/CSS" class="submenu-item "><div class="submenu-icon css"></div><div class="submenu-content-container"><div class="submenu-item-heading">CSS</div><p class="submenu-item-description">Code used to describe document style</p></div></a></li><li class="javascript-link-container "><a href="/en-US/docs/Web/JavaScript" class="submenu-item "><div class="submenu-icon javascript"></div><div class="submenu-content-container"><div class="submenu-item-heading">JavaScript</div><p class="submenu-item-description">General-purpose scripting language</p></div></a></li><li class="http-link-container "><a href="/en-US/docs/Web/HTTP" class="submenu-item "><div class="submenu-icon http"></div><div class="submenu-content-container"><div class="submenu-item-heading">HTTP</div><p class="submenu-item-description">Protocol for transmitting web resources</p></div></a></li><li class="apis-link-container "><a href="/en-US/docs/Web/API" class="submenu-item "><div class="submenu-icon apis"></div><div class="submenu-content-container"><div class="submenu-item-heading">Web APIs</div><p class="submenu-item-description">Interfaces for building web applications</p></div></a></li><li class="apis-link-container "><a href="/en-US/docs/Mozilla/Add-ons/WebExtensions" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Web Extensions</div><p class="submenu-item-description">Developing extensions for web browsers</p></div></a></li><li class=" "><a href="/en-US/docs/Web/Accessibility" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Accessibility</div><p class="submenu-item-description">Build web projects usable for all</p></div></a></li><li class="apis-link-container desktop-only "><a href="/en-US/docs/Web" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Web Technology</div><p class="submenu-item-description">Web technology reference for developers</p></div></a></li></ul></li><li class="top-level-entry-container "><button type="button" id="learn-button" class="top-level-entry menu-toggle" aria-controls="learn-menu" aria-expanded="false">Learn</button><a href="/en-US/docs/Learn_web_development" class="top-level-entry">Learn</a><ul id="learn-menu" class="submenu learn hidden inline-submenu-lg" aria-labelledby="learn-button"><li class="apis-link-container mobile-only "><a href="/en-US/docs/Learn_web_development" class="submenu-item "><div class="submenu-icon learn"></div><div class="submenu-content-container"><div class="submenu-item-heading">Overview / MDN Learning Area</div><p class="submenu-item-description">Learn web development</p></div></a></li><li class="apis-link-container desktop-only "><a href="/en-US/docs/Learn_web_development" class="submenu-item "><div class="submenu-icon learn"></div><div class="submenu-content-container"><div class="submenu-item-heading">MDN Learning Area</div><p class="submenu-item-description">Learn web development</p></div></a></li><li class="html-link-container "><a href="/en-US/docs/Learn_web_development/Core/Structuring_content" class="submenu-item "><div class="submenu-icon html"></div><div class="submenu-content-container"><div class="submenu-item-heading">HTML</div><p class="submenu-item-description">Learn to structure web content with HTML</p></div></a></li><li class="css-link-container "><a href="/en-US/docs/Learn_web_development/Core/Styling_basics" class="submenu-item "><div class="submenu-icon css"></div><div class="submenu-content-container"><div class="submenu-item-heading">CSS</div><p class="submenu-item-description">Learn to style content using CSS</p></div></a></li><li class="javascript-link-container "><a href="/en-US/docs/Learn_web_development/Core/Scripting" class="submenu-item "><div class="submenu-icon javascript"></div><div class="submenu-content-container"><div class="submenu-item-heading">JavaScript</div><p class="submenu-item-description">Learn to run scripts in the browser</p></div></a></li><li class=" "><a href="/en-US/docs/Learn_web_development/Core/Accessibility" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Accessibility</div><p class="submenu-item-description">Learn to make the web accessible to all</p></div></a></li></ul></li><li class="top-level-entry-container "><button type="button" id="mdn-plus-button" class="top-level-entry menu-toggle" aria-controls="mdn-plus-menu" aria-expanded="false">Plus</button><a href="/en-US/plus" class="top-level-entry">Plus</a><ul id="mdn-plus-menu" class="submenu mdn-plus hidden inline-submenu-lg" aria-labelledby="mdn-plus-button"><li class=" "><a href="/en-US/plus" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Overview</div><p class="submenu-item-description">A customized MDN experience</p></div></a></li><li class=" "><a href="/en-US/plus/ai-help" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">AI Help</div><p class="submenu-item-description">Get real-time assistance and support</p></div></a></li><li class=" "><a href="/en-US/plus/updates" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Updates</div><p class="submenu-item-description">All browser compatibility updates at a glance</p></div></a></li><li class=" "><a href="/en-US/plus/docs/features/overview" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Documentation</div><p class="submenu-item-description">Learn how to use MDN Plus</p></div></a></li><li class=" "><a href="/en-US/plus/docs/faq" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">FAQ</div><p class="submenu-item-description">Frequently asked questions about MDN Plus</p></div></a></li></ul></li><li class="top-level-entry-container "><a class="top-level-entry menu-link" href="/en-US/curriculum/">Curriculum <sup class="new">New</sup></a></li><li class="top-level-entry-container "><a class="top-level-entry menu-link" href="/en-US/blog/">Blog</a></li><li class="top-level-entry-container "><button type="button" id="tools-button" class="top-level-entry menu-toggle" aria-controls="tools-menu" aria-expanded="false">Tools</button><ul id="tools-menu" class="submenu tools hidden inline-submenu-lg" aria-labelledby="tools-button"><li class=" "><a href="/en-US/play" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">Playground</div><p class="submenu-item-description">Write, test and share your code</p></div></a></li><li class=" "><a href="/en-US/observatory" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">HTTP Observatory</div><p class="submenu-item-description">Scan a website for free</p></div></a></li><li class=" "><a href="/en-US/plus/ai-help" class="submenu-item "><div class="submenu-icon"></div><div class="submenu-content-container"><div class="submenu-item-heading">AI Help</div><p class="submenu-item-description">Get real-time assistance and support</p></div></a></li></ul></li></ul></nav><div class="header-search"><form action="/en-US/search" class="search-form search-widget" id="top-nav-search-form" role="search"><label id="top-nav-search-label" for="top-nav-search-input" class="visually-hidden">Search MDN</label><input aria-activedescendant="" aria-autocomplete="list" aria-controls="top-nav-search-menu" aria-expanded="false" aria-labelledby="top-nav-search-label" autoComplete="off" id="top-nav-search-input" role="combobox" type="search" class="search-input-field" name="q" placeholder=" " required="" value=""/><button type="button" class="button action has-icon clear-search-button"><span class="button-wrap"><span class="icon icon-cancel "></span><span class="visually-hidden">Clear search input</span></span></button><button type="submit" class="button action has-icon search-button"><span class="button-wrap"><span class="icon icon-search "></span><span class="visually-hidden">Search</span></span></button><div id="top-nav-search-menu" role="listbox" aria-labelledby="top-nav-search-label"></div></form></div><div class="theme-switcher-menu"><button type="button" class="button action has-icon theme-switcher-menu small" aria-haspopup="menu"><span class="button-wrap"><span class="icon icon-theme-os-default "></span>Theme</span></button></div><ul class="auth-container"><li><a href="/users/fxa/login/authenticate/?next=%2Fen-US%2Fdocs%2FWeb%2FJavaScript%2FReference%2FGlobal_Objects%2FJSON" class="login-link" rel="nofollow">Log in</a></li><li><a href="/users/fxa/login/authenticate/?next=%2Fen-US%2Fdocs%2FWeb%2FJavaScript%2FReference%2FGlobal_Objects%2FJSON" target="_self" rel="nofollow" class="button primary mdn-plus-subscribe-link"><span class="button-wrap">Sign up for free</span></a></li></ul></div></div></header><div class="article-actions-container"><div class="container"><button type="button" class="button action has-icon sidebar-button" aria-label="Expand sidebar" aria-expanded="false" aria-controls="sidebar-quicklinks"><span class="button-wrap"><span class="icon icon-sidebar "></span></span></button><nav class="breadcrumbs-container" aria-label="Breadcrumb"><ol typeof="BreadcrumbList" vocab="https://schema.org/" aria-label="breadcrumbs"><li property="itemListElement" typeof="ListItem"><a href="/en-US/docs/Web" class="breadcrumb" property="item" typeof="WebPage"><span property="name">References</span></a><meta property="position" content="1"/></li><li property="itemListElement" typeof="ListItem"><a href="/en-US/docs/Web/JavaScript" class="breadcrumb" property="item" typeof="WebPage"><span property="name">JavaScript</span></a><meta property="position" content="2"/></li><li property="itemListElement" typeof="ListItem"><a href="/en-US/docs/Web/JavaScript/Reference" class="breadcrumb" property="item" typeof="WebPage"><span property="name">Reference</span></a><meta property="position" content="3"/></li><li property="itemListElement" typeof="ListItem"><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects" class="breadcrumb" property="item" typeof="WebPage"><span property="name">Standard built-in objects</span></a><meta property="position" content="4"/></li><li property="itemListElement" typeof="ListItem"><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="breadcrumb-current-page" property="item" typeof="WebPage"><span property="name">JSON</span></a><meta property="position" content="5"/></li></ol></nav><div class="article-actions"><button type="button" class="button action has-icon article-actions-toggle" aria-label="Article actions"><span class="button-wrap"><span class="icon icon-ellipses "></span><span class="article-actions-dialog-heading">Article Actions</span></span></button><ul class="article-actions-entries"><li class="article-actions-entry"><div class="languages-switcher-menu open-on-focus-within"><button id="languages-switcher-button" type="button" class="button action small has-icon languages-switcher-menu" aria-haspopup="menu"><span class="button-wrap"><span class="icon icon-language "></span>English (US)</span></button><div class="hidden"><ul class="submenu language-menu " aria-labelledby="language-menu-button"><li class=" "><form class="submenu-item locale-redirect-setting"><div class="group"><label class="switch"><input type="checkbox" name="locale-redirect"/><span class="slider"></span><span class="label">Remember language</span></label><a href="https://github.com/orgs/mdn/discussions/739" rel="external noopener noreferrer" target="_blank" title="Enable this setting to automatically switch to this language when it's available. (Click to learn more.)"><span class="icon icon-question-mark "></span></a></div></form></li><li class=" "><a data-locale="de" href="/de/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>Deutsch</span><span title="Diese Übersetzung ist Teil eines Experiments."><span class="icon icon-experimental "></span></span></a></li><li class=" "><a data-locale="es" href="/es/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>Español</span></a></li><li class=" "><a data-locale="fr" href="/fr/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>Français</span></a></li><li class=" "><a data-locale="ja" href="/ja/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>日本語</span></a></li><li class=" "><a data-locale="ko" href="/ko/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>한국어</span></a></li><li class=" "><a data-locale="pt-BR" href="/pt-BR/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>Português (do Brasil)</span></a></li><li class=" "><a data-locale="ru" href="/ru/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>Русский</span></a></li><li class=" "><a data-locale="zh-CN" href="/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>中文 (简体)</span></a></li><li class=" "><a data-locale="zh-TW" href="/zh-TW/docs/Web/JavaScript/Reference/Global_Objects/JSON" class="button submenu-item"><span>正體中文 (繁體)</span></a></li></ul></div></div></li></ul></div></div></div></div><div class="main-wrapper"><div class="sidebar-container"><aside id="sidebar-quicklinks" class="sidebar"><button type="button" class="button action backdrop" aria-label="Collapse sidebar"><span class="button-wrap"></span></button><nav aria-label="Related Topics" class="sidebar-inner"><header class="sidebar-actions"><section class="sidebar-filter-container"><div class="sidebar-filter "><label id="sidebar-filter-label" class="sidebar-filter-label" for="sidebar-filter-input"><span class="icon icon-filter"></span><span class="visually-hidden">Filter sidebar</span></label><input id="sidebar-filter-input" autoComplete="off" class="sidebar-filter-input-field false" type="text" placeholder="Filter" value=""/><button type="button" class="button action has-icon clear-sidebar-filter-button"><span class="button-wrap"><span class="icon icon-cancel "></span><span class="visually-hidden">Clear filter input</span></span></button></div></section></header><div class="sidebar-inner-nav"><div class="in-nav-toc"><div class="document-toc-container"><section class="document-toc"><header><h2 class="document-toc-heading">In this article</h2></header><ul class="document-toc-list"><li class="document-toc-item "><a class="document-toc-link" href="#description">Description</a></li><li class="document-toc-item "><a class="document-toc-link" href="#static_properties">Static properties</a></li><li class="document-toc-item "><a class="document-toc-link" href="#static_methods">Static methods</a></li><li class="document-toc-item "><a class="document-toc-link" href="#examples">Examples</a></li><li class="document-toc-item "><a class="document-toc-link" href="#specifications">Specifications</a></li><li class="document-toc-item "><a class="document-toc-link" href="#browser_compatibility">Browser compatibility</a></li><li class="document-toc-item "><a class="document-toc-link" href="#see_also">See also</a></li></ul></section></div></div><div class="sidebar-body"><ol><li class="section"><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects">Standard built-in objects</a></li><li class="section"><em><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON" aria-current="page"><code>JSON</code></a></em></li><li class="toggle"><details open=""><summary>Static methods</summary><ol><li><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/isRawJSON"><code>JSON.isRawJSON()</code></a></li><li><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse"><code>JSON.parse()</code></a></li><li><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/rawJSON"><code>JSON.rawJSON()</code></a></li><li><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify"><code>JSON.stringify()</code></a></li></ol></details></li></ol></div></div><section class="place side"></section></nav></aside><div class="toc-container"><aside class="toc"><nav><div class="document-toc-container"><section class="document-toc"><header><h2 class="document-toc-heading">In this article</h2></header><ul class="document-toc-list"><li class="document-toc-item "><a class="document-toc-link" href="#description">Description</a></li><li class="document-toc-item "><a class="document-toc-link" href="#static_properties">Static properties</a></li><li class="document-toc-item "><a class="document-toc-link" href="#static_methods">Static methods</a></li><li class="document-toc-item "><a class="document-toc-link" href="#examples">Examples</a></li><li class="document-toc-item "><a class="document-toc-link" href="#specifications">Specifications</a></li><li class="document-toc-item "><a class="document-toc-link" href="#browser_compatibility">Browser compatibility</a></li><li class="document-toc-item "><a class="document-toc-link" href="#see_also">See also</a></li></ul></section></div></nav></aside><section class="place side"></section></div></div><main id="content" class="main-content "><article class="main-page-content" lang="en-US"><header><h1>JSON</h1><details class="baseline-indicator high"><summary><span class="indicator" role="img" aria-label="Baseline Check"></span><div class="status-title">Baseline <span class="not-bold">Widely available</span> *</div><div class="browsers"><span class="engine" title="Supported in Chrome and Edge"><span class="browser chrome supported" role="img" aria-label="Chrome check"></span><span class="browser edge supported" role="img" aria-label="Edge check"></span></span><span class="engine" title="Supported in Firefox"><span class="browser firefox supported" role="img" aria-label="Firefox check"></span></span><span class="engine" title="Supported in Safari"><span class="browser safari supported" role="img" aria-label="Safari check"></span></span></div><span class="icon icon-chevron "></span></summary><div class="extra"><p>This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.</p><p>* Some parts of this feature may have varying levels of support.</p><ul><li><a href="/en-US/docs/Glossary/Baseline/Compatibility" data-glean="baseline_link_learn_more" target="_blank" class="learn-more">Learn more</a></li><li><a href="#browser_compatibility" data-glean="baseline_link_bcd_table">See full compatibility</a></li><li><a href="https://survey.alchemer.com/s3/7634825/MDN-baseline-feedback?page=%2Fen-US%2Fdocs%2FWeb%2FJavaScript%2FReference%2FGlobal_Objects%2FJSON&level=high" data-glean="baseline_link_feedback" class="feedback-link" target="_blank" rel="noreferrer">Report feedback</a></li></ul></div></details></header><div class="section-content"><p>The <strong><code>JSON</code></strong> namespace object contains static methods for parsing values from and converting values to <a href="https://json.org/" class="external" target="_blank">JavaScript Object Notation</a> (<a href="/en-US/docs/Glossary/JSON">JSON</a>).</p></div><section aria-labelledby="description"><h2 id="description"><a href="#description">Description</a></h2><div class="section-content"><p>Unlike most global objects, <code>JSON</code> is not a constructor. You cannot use it with the <a href="/en-US/docs/Web/JavaScript/Reference/Operators/new"><code>new</code> operator</a> or invoke the <code>JSON</code> object as a function. All properties and methods of <code>JSON</code> are static (just like the <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math"><code>Math</code></a> object).</p></div></section><section aria-labelledby="javascript_and_json_differences"><h3 id="javascript_and_json_differences"><a href="#javascript_and_json_differences">JavaScript and JSON differences</a></h3><div class="section-content"><p>JSON is a syntax for serializing objects, arrays, numbers, strings, booleans, and <a href="/en-US/docs/Web/JavaScript/Reference/Operators/null"><code>null</code></a>. It is based upon JavaScript syntax, but is distinct from JavaScript: most of JavaScript is <em>not</em> JSON. For example:</p> <dl> <dt id="objects_and_arrays"><a href="#objects_and_arrays">Objects and Arrays</a></dt> <dd> <p>Property names must be double-quoted strings; <a href="/en-US/docs/Web/JavaScript/Reference/Trailing_commas">trailing commas</a> are forbidden.</p> </dd> <dt id="numbers"><a href="#numbers">Numbers</a></dt> <dd> <p>Leading zeros are prohibited. A decimal point must be followed by at least one digit. <code>NaN</code> and <code>Infinity</code> are unsupported.</p> </dd> </dl> <p>Any JSON text is a valid JavaScript expression, but only after the <a href="https://github.com/tc39/proposal-json-superset" class="external" target="_blank">JSON superset</a> revision. Before the revision, U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR are allowed in string literals and property keys in JSON; but the same use in JavaScript string literals is a <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/SyntaxError"><code>SyntaxError</code></a>.</p> <p>Other differences include allowing only double-quoted strings and no support for <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/undefined"><code>undefined</code></a> or comments. For those who wish to use a more human-friendly configuration format based on JSON, there is <a href="https://json5.org/" class="external" target="_blank">JSON5</a>, used by the Babel compiler, and the more commonly used <a href="https://en.wikipedia.org/wiki/YAML" class="external" target="_blank">YAML</a>.</p> <p>The same text may represent different values in JavaScript object literals vs. JSON as well. For more information, see <a href="/en-US/docs/Web/JavaScript/Reference/Operators/Object_initializer#object_literal_syntax_vs._json">Object literal syntax vs. JSON</a>.</p></div></section><section aria-labelledby="full_json_grammar"><h3 id="full_json_grammar"><a href="#full_json_grammar">Full JSON grammar</a></h3><div class="section-content"><p>Valid JSON syntax is formally defined by the following grammar, expressed in <a href="https://en.wikipedia.org/wiki/Augmented_Backus%E2%80%93Naur_form" class="external" target="_blank">ABNF</a>, and copied from <a href="https://datatracker.ietf.org/doc/html/rfc8259" class="external" target="_blank">IETF JSON standard (RFC)</a>:</p> <pre class="brush: plain notranslate">JSON-text = object / array begin-array = ws %x5B ws ; [ left square bracket begin-object = ws %x7B ws ; { left curly bracket end-array = ws %x5D ws ; ] right square bracket end-object = ws %x7D ws ; } right curly bracket name-separator = ws %x3A ws ; : colon value-separator = ws %x2C ws ; , comma ws = *( %x20 / ; Space %x09 / ; Horizontal tab %x0A / ; Line feed or New line %x0D ; Carriage return ) value = false / null / true / object / array / number / string false = %x66.61.6c.73.65 ; false null = %x6e.75.6c.6c ; null true = %x74.72.75.65 ; true object = begin-object [ member *( value-separator member ) ] end-object member = string name-separator value array = begin-array [ value *( value-separator value ) ] end-array number = [ minus ] int [ frac ] [ exp ] decimal-point = %x2E ; . digit1-9 = %x31-39 ; 1-9 e = %x65 / %x45 ; e E exp = e [ minus / plus ] 1*DIGIT frac = decimal-point 1*DIGIT int = zero / ( digit1-9 *DIGIT ) minus = %x2D ; - plus = %x2B ; + zero = %x30 ; 0 string = quotation-mark *char quotation-mark char = unescaped / escape ( %x22 / ; " quotation mark U+0022 %x5C / ; \ reverse solidus U+005C %x2F / ; / solidus U+002F %x62 / ; b backspace U+0008 %x66 / ; f form feed U+000C %x6E / ; n line feed U+000A %x72 / ; r carriage return U+000D %x74 / ; t tab U+0009 %x75 4HEXDIG ) ; uXXXX U+XXXX escape = %x5C ; \ quotation-mark = %x22 ; " unescaped = %x20-21 / %x23-5B / %x5D-10FFFF HEXDIG = DIGIT / %x41-46 / %x61-66 ; 0-9, A-F, or a-f ; HEXDIG equivalent to HEXDIG rule in [RFC5234] DIGIT = %x30-39 ; 0-9 ; DIGIT equivalent to DIGIT rule in [RFC5234] </pre> <p>Insignificant <a href="/en-US/docs/Glossary/Whitespace">whitespace</a> may be present anywhere except within a <code>JSONNumber</code> (numbers must contain no whitespace) or <code>JSONString</code> (where it is interpreted as the corresponding character in the string, or would cause an error). The tab (U+0009), carriage return (U+000D), line feed (U+000A), and space (U+0020) characters are the only valid whitespace characters.</p></div></section><section aria-labelledby="static_properties"><h2 id="static_properties"><a href="#static_properties">Static properties</a></h2><div class="section-content"><dl> <dt id="jsonsymbol.tostringtag"><a href="#jsonsymbol.tostringtag"><code>JSON[Symbol.toStringTag]</code></a></dt> <dd> <p>The initial value of the <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag"><code>[Symbol.toStringTag]</code></a> property is the string <code>"JSON"</code>. This property is used in <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/toString"><code>Object.prototype.toString()</code></a>.</p> </dd> </dl></div></section><section aria-labelledby="static_methods"><h2 id="static_methods"><a href="#static_methods">Static methods</a></h2><div class="section-content"><dl> <dt id="json.israwjson"><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/isRawJSON"><code>JSON.isRawJSON()</code></a></dt> <dd> <p>Tests whether a value is an object returned by <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/rawJSON"><code>JSON.rawJSON()</code></a>.</p> </dd> <dt id="json.parse"><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse"><code>JSON.parse()</code></a></dt> <dd> <p>Parse a piece of string text as JSON, optionally transforming the produced value and its properties, and return the value.</p> </dd> <dt id="json.rawjson"><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/rawJSON"><code>JSON.rawJSON()</code></a></dt> <dd> <p>Creates a "raw JSON" object containing a piece of JSON text. When serialized to JSON, the raw JSON object is treated as if it is already a piece of JSON. This text is required to be valid JSON.</p> </dd> <dt id="json.stringify"><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify"><code>JSON.stringify()</code></a></dt> <dd> <p>Return a JSON string corresponding to the specified value, optionally including only certain properties or replacing property values in a user-defined manner.</p> </dd> </dl></div></section><section aria-labelledby="examples"><h2 id="examples"><a href="#examples">Examples</a></h2><div class="section-content"></div></section><section aria-labelledby="example_json"><h3 id="example_json"><a href="#example_json">Example JSON</a></h3><div class="section-content"><div class="code-example"><div class="example-header"><span class="language-name">json</span></div><pre class="brush: json notranslate"><code>{ "browsers": { "firefox": { "name": "Firefox", "pref_url": "about:config", "releases": { "1": { "release_date": "2004-11-09", "status": "retired", "engine": "Gecko", "engine_version": "1.7" } } } } } </code></pre></div> <p>You can use the <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse"><code>JSON.parse()</code></a> method to convert the above JSON string into a JavaScript object:</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const jsonText = `{ "browsers": { "firefox": { "name": "Firefox", "pref_url": "about:config", "releases": { "1": { "release_date": "2004-11-09", "status": "retired", "engine": "Gecko", "engine_version": "1.7" } } } } }`; console.log(JSON.parse(jsonText)); </code></pre></div></div></section><section aria-labelledby="lossless_number_serialization"><h3 id="lossless_number_serialization"><a href="#lossless_number_serialization">Lossless number serialization</a></h3><div class="section-content"><p>JSON can contain number literals of arbitrary precision. However, it is not possible to represent all JSON numbers exactly in JavaScript, because JavaScript uses floating point representation which has a fixed precision. For example, <code>12345678901234567890 === 12345678901234567000</code> in JavaScript because they have the same floating point representation. This means there is no JavaScript number that corresponds precisely to the <code>12345678901234567890</code> JSON number.</p> <p>Let's assume you have a exact representation of some number (either via <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt"><code>BigInt</code></a> or a custom library):</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const data = { // Using a BigInt here to store the exact value, // but it can also be a custom high-precision number library, // if the number might not be an integer. gross_gdp: 12345678901234567890n, }; </code></pre></div> <p>You want to serialize it and then parse to the same exact number. There are several difficulties:</p> <ul> <li>On the serialization side, in order to obtain a number in JSON, you have to pass a number to <code>JSON.stringify</code>, either via the <code>replacer</code> function or via the <code>toJSON</code> method. But, in either case, you have already lost precision during number conversion. If you pass a string to <code>JSON.stringify</code>, it will be serialized as a string, not a number.</li> <li>On the parsing side, not all numbers can be represented exactly. For example, <code>JSON.parse("12345678901234567890")</code> returns <code>12345678901234568000</code> because the number is rounded to the nearest representable number. Even if you use a <code>reviver</code> function, the number will already be rounded before the <code>reviver</code> function is called.</li> </ul> <p>There are, in general, two ways to ensure that numbers are losslessly converted to JSON and parsed back: one involves a JSON number, another involves a JSON string. JSON is a <em>communication format</em>, so if you use JSON, you are likely communicating with another system (HTTP request, storing in database, etc.). The best solution to choose depends on the recipient system.</p> <h4 id="using_json_strings">Using JSON strings</h4> <p>If the recipient system does not have same JSON-handling capabilities as JavaScript, and does not support high precision numbers, you may want to serialize the number as a string, and then handle it as a string on the recipient side. This is also the only option in older JavaScript.</p> <p>To specify how custom data types (including <code>BigInt</code>) should be serialized to JSON, either add a <code>toJSON</code> method to your data type, or use the <code>replacer</code> function of <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify"><code>JSON.stringify()</code></a>.</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>// Using toJSON() method BigInt.prototype.toJSON = function () { return this.toString(); }; const str1 = JSON.stringify(data); // Using JSON.stringify() with replacer const str2 = JSON.stringify(data, (key, value) => { if (key === "gross_gdp") { return value.toString(); } return value; }); </code></pre></div> <p>In either case, the JSON text will look like <code>{"gross_gdp":"12345678901234567890"}</code>, where the value is a string, not a number. Then, on the recipient side, you can parse the JSON and handle the string.</p> <h4 id="using_json_numbers">Using JSON numbers</h4> <p>If the recipient of this message natively supports high precision numbers (such as Python integers), passing numbers as JSON numbers is obviously better, because they can directly parse to the high precision type instead of parsing a string from JSON, and then parsing a number from the string. In JavaScript, you can serialize arbitrary data types to JSON numbers without producing a number value first (resulting in loss of precision) by using <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/rawJSON"><code>JSON.rawJSON()</code></a> to precisely specify what the JSON source text should be.</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>// Using toJSON() method BigInt.prototype.toJSON = function () { return JSON.rawJSON(this.toString()); }; const str1 = JSON.stringify(data); // Using JSON.stringify() with replacer const str2 = JSON.stringify(data, (key, value) => { if (key === "gross_gdp") { return JSON.rawJSON(value.toString()); } return value; }); </code></pre></div> <p>The text passed to <code>JSON.rawJSON</code> is treated as if it is already a piece of JSON, so it won't be serialized again as a string. Therefore, the JSON text will look like <code>{"gross_gdp":12345678901234567890}</code>, where the value is a number. This JSON can then be parsed by the recipient without any extra processing, provided that the recipient system does not have the same precision limitations as JavaScript.</p> <p>When parsing JSON containing high-precision numbers in JavaScript, take extra care because when <code>JSON.parse()</code> invokes the <code>reviver</code> function, the value you receive is already parsed (and has lost precision). You can use the <code>context.source</code> parameter of the <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse"><code>JSON.parse()</code></a> <code>reviver</code> function to re-parse the number yourself.</p> <div class="code-example"><div class="example-header"><span class="language-name">js</span></div><pre class="brush: js notranslate"><code>const parsedData = JSON.parse(str, (key, value, context) => { if (key === "gross_gdp") { // Or use the constructor of your custom high-precision number library return BigInt(context.source); } return value; }); // { gross_gdp: 12345678901234567890n } </code></pre></div></div></section><h2 id="specifications"><a href="#specifications">Specifications</a></h2><table class="standard-table"><thead><tr><th scope="col">Specification</th></tr></thead><tbody><tr><td><a href="https://tc39.es/ecma262/multipage/structured-data.html#sec-json-object">ECMAScript® 2025 Language Specification <br/><small># sec-json-object</small></a></td></tr></tbody></table><h2 id="browser_compatibility"><a href="#browser_compatibility">Browser compatibility</a></h2><p>BCD tables only load in the browser<noscript> with JavaScript enabled. Enable JavaScript to view data.</noscript></p><section aria-labelledby="see_also"><h2 id="see_also"><a href="#see_also">See also</a></h2><div class="section-content"><ul> <li><a href="https://json-diff.com/" class="external" target="_blank">JSON Diff</a></li> <li><a href="https://jsonbeautifier.org/" class="external" target="_blank">JSON Beautifier/editor</a></li> <li><a href="https://jsonparser.org/" class="external" target="_blank">JSON Parser</a></li> <li><a href="https://tools.learningcontainer.com/json-validator/" class="external" target="_blank">JSON Validator</a></li> </ul></div></section></article><aside class="article-footer"><div class="article-footer-inner"><div class="svg-container"><svg xmlns="http://www.w3.org/2000/svg" width="162" height="162" viewBox="0 0 162 162" fill="none" role="none"><mask id="b" fill="#fff"><path d="M97.203 47.04c8.113-7.886 18.004-13.871 28.906-17.492a78 78 0 0 1 33.969-3.39c11.443 1.39 22.401 5.295 32.024 11.411s17.656 14.28 23.476 23.86c5.819 9.579 9.269 20.318 10.083 31.385a69.85 69.85 0 0 1-5.387 32.44c-4.358 10.272-11.115 19.443-19.747 26.801-8.632 7.359-18.908 12.709-30.034 15.637l-6.17-21.698c7.666-2.017 14.746-5.703 20.694-10.773 5.948-5.071 10.603-11.389 13.606-18.467a48.14 48.14 0 0 0 3.712-22.352c-.561-7.625-2.938-15.025-6.948-21.625s-9.544-12.226-16.175-16.44-14.181-6.904-22.065-7.863a53.75 53.75 0 0 0-23.405 2.336c-7.513 2.495-14.327 6.62-19.918 12.053z"></path></mask><path stroke="url(#a)" stroke-dasharray="6, 6" stroke-width="2" d="M97.203 47.04c8.113-7.886 18.004-13.871 28.906-17.492a78 78 0 0 1 33.969-3.39c11.443 1.39 22.401 5.295 32.024 11.411s17.656 14.28 23.476 23.86c5.819 9.579 9.269 20.318 10.083 31.385a69.85 69.85 0 0 1-5.387 32.44c-4.358 10.272-11.115 19.443-19.747 26.801-8.632 7.359-18.908 12.709-30.034 15.637l-6.17-21.698c7.666-2.017 14.746-5.703 20.694-10.773 5.948-5.071 10.603-11.389 13.606-18.467a48.14 48.14 0 0 0 3.712-22.352c-.561-7.625-2.938-15.025-6.948-21.625s-9.544-12.226-16.175-16.44-14.181-6.904-22.065-7.863a53.75 53.75 0 0 0-23.405 2.336c-7.513 2.495-14.327 6.62-19.918 12.053z" mask="url(#b)" style="stroke:url(#a)" transform="translate(-63.992 -25.587)"></path><ellipse cx="8.066" cy="111.597" fill="var(--background-tertiary)" rx="53.677" ry="53.699" transform="matrix(.71707 -.697 .7243 .6895 0 0)"></ellipse><g clip-path="url(#c)" transform="translate(-63.992 -25.587)"><path fill="#9abff5" d="m144.256 137.379 32.906 12.434a4.41 4.41 0 0 1 2.559 5.667l-9.326 24.679a4.41 4.41 0 0 1-5.667 2.559l-8.226-3.108-2.332 6.17c-.466 1.233-.375 1.883-1.609 1.417l-2.253-.527c-.411-.155-.95-.594-1.206-1.161l-4.734-10.484-12.545-4.741a4.41 4.41 0 0 1-2.559-5.667l9.325-24.679a4.41 4.41 0 0 1 5.667-2.559m9.961 29.617 8.227 3.108 3.264-8.638-.498-6.768-4.113-1.555.548 7.258-4.319-1.632zm-12.339-4.663 8.226 3.108 3.264-8.637-.498-6.769-4.113-1.554.548 7.257-4.319-1.632z"></path></g><g clip-path="url(#d)" transform="translate(-63.992 -25.587)"><path fill="#81b0f3" d="M135.35 60.136 86.67 41.654c-3.346-1.27-7.124.428-8.394 3.775L64.414 81.938c-1.27 3.347.428 7.125 3.774 8.395l12.17 4.62-3.465 9.128c-.693 1.826-1.432 2.457.394 3.15l3.014 1.625c.609.231 1.637.274 2.477-.104l15.53-6.983 18.56 7.047c3.346 1.27 7.124-.428 8.395-3.775l13.862-36.51c1.27-3.346-.428-7.124-3.775-8.395M95.261 83.207l-12.17-4.62 4.852-12.779 7.19-7.017 6.085 2.31-7.725 7.51 6.389 2.426zm18.255 6.93-12.17-4.62 4.852-12.778 7.189-7.017 6.085 2.31-7.725 7.51 6.39 2.426z"></path></g><defs><clipPath id="c"><path fill="#fff" d="m198.638 146.586-65.056-24.583-24.583 65.057 65.056 24.582z"></path></clipPath><clipPath id="d"><path fill="#fff" d="m66.438 14.055 96.242 36.54-36.54 96.243-96.243-36.54z"></path></clipPath><linearGradient id="a" x1="97.203" x2="199.995" y1="47.04" y2="152.793" gradientUnits="userSpaceOnUse"><stop stop-color="#086DFC"></stop><stop offset="0.246" stop-color="#2C81FA"></stop><stop offset="0.516" stop-color="#5497F8"></stop><stop offset="0.821" stop-color="#80B0F6"></stop><stop offset="1" stop-color="#9ABFF5"></stop></linearGradient></defs></svg></div><h2>Help improve MDN</h2><fieldset class="feedback"><label>Was this page helpful to you?</label><div class="button-container"><button type="button" class="button primary has-icon yes"><span class="button-wrap"><span class="icon icon-thumbs-up "></span>Yes</span></button><button type="button" class="button primary has-icon no"><span class="button-wrap"><span class="icon icon-thumbs-down "></span>No</span></button></div></fieldset><a class="contribute" href="https://github.com/mdn/content/blob/main/CONTRIBUTING.md" title="This will take you to our contribution guidelines on GitHub." target="_blank" rel="noopener noreferrer">Learn how to contribute</a>.<p class="last-modified-date">This page was last modified on <time dateTime="2025-01-20T22:28:20.000Z">Jan 20, 2025</time> by <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/contributors.txt" rel="nofollow">MDN contributors</a>.</p><div id="on-github" class="on-github"><a href="https://github.com/mdn/content/blob/main/files/en-us/web/javascript/reference/global_objects/json/index.md?plain=1" title="Folder: en-us/web/javascript/reference/global_objects/json (Opens in a new tab)" target="_blank" rel="noopener noreferrer">View this page on GitHub</a> • <a href="https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FWeb%2FJavaScript%2FReference%2FGlobal_Objects%2FJSON&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fweb%2Fjavascript%2Freference%2Fglobal_objects%2Fjson%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FWeb%2FJavaScript%2FReference%2FGlobal_Objects%2FJSON%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fweb%2Fjavascript%2Freference%2Fglobal_objects%2Fjson%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2Fa4e9bce1e8bac1b845b32536e0e44f335233eab6%0A*+Document+last+modified%3A+2025-01-20T22%3A28%3A20.000Z%0A%0A%3C%2Fdetails%3E" title="This will take you to GitHub to file a new issue." target="_blank" rel="noopener noreferrer">Report a problem with this content</a></div></div></aside></main></div></div><footer id="nav-footer" class="page-footer"><div class="page-footer-grid"><div class="page-footer-logo-col"><a href="/" class="mdn-footer-logo" aria-label="MDN homepage"><svg width="48" height="17" viewBox="0 0 48 17" fill="none" xmlns="http://www.w3.org/2000/svg"><title id="mdn-footer-logo-svg">MDN logo</title><path d="M20.04 16.512H15.504V10.416C15.504 9.488 15.344 8.824 15.024 8.424C14.72 8.024 14.264 7.824 13.656 7.824C12.92 7.824 12.384 8.064 12.048 8.544C11.728 9.024 11.568 9.64 11.568 10.392V14.184H13.008V16.512H8.472V10.416C8.472 9.488 8.312 8.824 7.992 8.424C7.688 8.024 7.232 7.824 6.624 7.824C5.872 7.824 5.336 8.064 5.016 8.544C4.696 9.024 4.536 9.64 4.536 10.392V14.184H6.6V16.512H0V14.184H1.44V8.04H0.024V5.688H4.536V7.32C5.224 6.088 6.32 5.472 7.824 5.472C8.608 5.472 9.328 5.664 9.984 6.048C10.64 6.432 11.096 7.016 11.352 7.8C11.992 6.248 13.168 5.472 14.88 5.472C15.856 5.472 16.72 5.776 17.472 6.384C18.224 6.992 18.6 7.936 18.6 9.216V14.184H20.04V16.512Z" fill="currentColor"></path><path d="M33.6714 16.512H29.1354V14.496C28.8314 15.12 28.3834 15.656 27.7914 16.104C27.1994 16.536 26.4154 16.752 25.4394 16.752C24.0154 16.752 22.8954 16.264 22.0794 15.288C21.2634 14.312 20.8554 12.984 20.8554 11.304C20.8554 9.688 21.2554 8.312 22.0554 7.176C22.8554 6.04 24.0634 5.472 25.6794 5.472C26.5594 5.472 27.2794 5.648 27.8394 6C28.3994 6.352 28.8314 6.8 29.1354 7.344V2.352H26.9754V0H32.2314V14.184H33.6714V16.512ZM29.1354 11.04V10.776C29.1354 9.88 28.8954 9.184 28.4154 8.688C27.9514 8.176 27.3674 7.92 26.6634 7.92C25.9754 7.92 25.3674 8.176 24.8394 8.688C24.3274 9.2 24.0714 10.008 24.0714 11.112C24.0714 12.152 24.3114 12.944 24.7914 13.488C25.2714 14.032 25.8394 14.304 26.4954 14.304C27.3114 14.304 27.9514 13.96 28.4154 13.272C28.8954 12.584 29.1354 11.84 29.1354 11.04Z" fill="currentColor"></path><path d="M47.9589 16.512H41.9829V14.184H43.4229V10.416C43.4229 9.488 43.2629 8.824 42.9429 8.424C42.6389 8.024 42.1829 7.824 41.5749 7.824C40.8389 7.824 40.2709 8.056 39.8709 8.52C39.4709 8.968 39.2629 9.56 39.2469 10.296V14.184H40.6869V16.512H34.7109V14.184H36.1509V8.04H34.5909V5.688H39.2469V7.344C39.9669 6.096 41.1269 5.472 42.7269 5.472C43.7509 5.472 44.6389 5.776 45.3909 6.384C46.1429 6.992 46.5189 7.936 46.5189 9.216V14.184H47.9589V16.512Z" fill="currentColor"></path></svg></a><p>Your blueprint for a better internet.</p><ul class="social-icons"><li><a href="https://mastodon.social/@mdn" target="_blank" rel="me noopener noreferrer"><span class="icon icon-mastodon"></span><span class="visually-hidden">MDN on Mastodon</span></a></li><li><a href="https://twitter.com/mozdevnet" target="_blank" rel="noopener noreferrer"><span class="icon icon-twitter-x"></span><span class="visually-hidden">MDN on X (formerly Twitter)</span></a></li><li><a href="https://github.com/mdn/" target="_blank" rel="noopener noreferrer"><span class="icon icon-github-mark-small"></span><span class="visually-hidden">MDN on GitHub</span></a></li><li><a href="/en-US/blog/rss.xml" target="_blank"><span class="icon icon-feed"></span><span class="visually-hidden">MDN Blog RSS Feed</span></a></li></ul></div><div class="page-footer-nav-col-1"><h2 class="footer-nav-heading">MDN</h2><ul class="footer-nav-list"><li class="footer-nav-item"><a href="/en-US/about">About</a></li><li class="footer-nav-item"><a href="/en-US/blog/">Blog</a></li><li class="footer-nav-item"><a href="https://www.mozilla.org/en-US/careers/listings/?team=ProdOps" target="_blank" rel="noopener noreferrer">Careers</a></li><li class="footer-nav-item"><a href="/en-US/advertising">Advertise with us</a></li></ul></div><div class="page-footer-nav-col-2"><h2 class="footer-nav-heading">Support</h2><ul class="footer-nav-list"><li class="footer-nav-item"><a class="footer-nav-link" href="https://support.mozilla.org/products/mdn-plus">Product help</a></li><li class="footer-nav-item"><a class="footer-nav-link" href="/en-US/docs/MDN/Community/Issues">Report an issue</a></li></ul></div><div class="page-footer-nav-col-3"><h2 class="footer-nav-heading">Our communities</h2><ul class="footer-nav-list"><li class="footer-nav-item"><a class="footer-nav-link" href="/en-US/community">MDN Community</a></li><li class="footer-nav-item"><a class="footer-nav-link" href="https://discourse.mozilla.org/c/mdn/236" target="_blank" rel="noopener noreferrer">MDN Forum</a></li><li class="footer-nav-item"><a class="footer-nav-link" href="/discord" target="_blank" rel="noopener noreferrer">MDN Chat</a></li></ul></div><div class="page-footer-nav-col-4"><h2 class="footer-nav-heading">Developers</h2><ul class="footer-nav-list"><li class="footer-nav-item"><a class="footer-nav-link" href="/en-US/docs/Web">Web Technologies</a></li><li class="footer-nav-item"><a class="footer-nav-link" href="/en-US/docs/Learn">Learn Web Development</a></li><li class="footer-nav-item"><a class="footer-nav-link" href="/en-US/plus">MDN Plus</a></li><li class="footer-nav-item"><a href="https://hacks.mozilla.org/" target="_blank" rel="noopener noreferrer">Hacks Blog</a></li></ul></div><div class="page-footer-moz"><a href="https://www.mozilla.org/" class="footer-moz-logo-link" target="_blank" rel="noopener noreferrer"><svg xmlns="http://www.w3.org/2000/svg" width="137" height="32" fill="none" viewBox="0 0 267.431 62.607"><path fill="currentColor" d="m13.913 23.056 5.33 25.356h2.195l5.33-25.356h14.267v38.976h-7.578V29.694h-2.194l-7.264 32.337h-7.343L9.418 29.694H7.223v32.337H-.354V23.056Zm47.137 9.123c9.12 0 14.423 5.385 14.423 15.214s-5.33 15.214-14.423 15.214c-9.12 0-14.423-5.385-14.423-15.214 0-9.855 5.304-15.214 14.423-15.214m0 24.363c4.285 0 6.428-2.196 6.428-7.032v-4.287c0-4.836-2.143-7.032-6.428-7.032s-6.428 2.196-6.428 7.032v4.287c0 4.836 2.143 7.032 6.428 7.032m18.473-.157 15.47-18.01h-15.26v-5.647h24.352v5.646L88.616 56.385h15.704v5.646H79.523Zm29.318-23.657h11.183V62.03h-7.578V38.375h-3.632v-5.646zm3.605-9.672h7.578v5.646h-7.578zm13.17 0h11.21v38.976h-7.578v-33.33h-3.632zm16.801 0H153.6v38.976h-7.577v-33.33h-3.632v-5.646zm29.03 9.123c4.442 0 7.394 2.143 8.231 5.881h2.194v-5.332h9.276v5.646h-3.632v18.011h3.632v5.646h-4.442c-3.135 0-4.834-1.699-4.834-4.836V56.7h-2.194c-.81 3.738-3.789 5.881-8.23 5.881-6.978 0-11.916-5.829-11.916-15.214 0-9.384 4.938-15.187 11.915-15.187m2.3 24.363c4.284 0 6.192-2.196 6.192-7.032v-4.287c0-4.836-1.908-7.032-6.193-7.032-4.18 0-6.193 2.196-6.193 7.032v4.287c0 4.836 2.012 7.032 6.193 7.032m48.34 5.489h-7.577V0h7.577zm6.585-29.643h32.165v-2.196l-21.295-7.634v-6.143l21.295-7.633V6.588h-25.345V0h32.165v12.522l-17.35 5.881V20.6l17.35 5.882v12.521h-38.985zm0-25.801h6.794v6.796h-6.794z"></path></svg></a><ul class="footer-moz-list"><li class="footer-moz-item"><a href="https://www.mozilla.org/privacy/websites/" class="footer-moz-link" target="_blank" rel="noopener noreferrer">Website Privacy Notice</a></li><li class="footer-moz-item"><a href="https://www.mozilla.org/privacy/websites/#cookies" class="footer-moz-link" target="_blank" rel="noopener noreferrer">Cookies</a></li><li class="footer-moz-item"><a href="https://www.mozilla.org/about/legal/terms/mozilla" class="footer-moz-link" target="_blank" rel="noopener noreferrer">Legal</a></li><li class="footer-moz-item"><a href="https://www.mozilla.org/about/governance/policies/participation/" class="footer-moz-link" target="_blank" rel="noopener noreferrer">Community Participation Guidelines</a></li></ul></div><div class="page-footer-legal"><p id="license" class="page-footer-legal-text">Visit <a href="https://www.mozilla.org" target="_blank" rel="noopener noreferrer">Mozilla Corporation’s</a> not-for-profit parent, the <a target="_blank" rel="noopener noreferrer" href="https://foundation.mozilla.org/">Mozilla Foundation</a>.<br/>Portions of this content are ©1998–2025 by individual mozilla.org contributors. Content available under <a href="/en-US/docs/MDN/Writing_guidelines/Attrib_copyright_license">a Creative Commons license</a>.</p></div></div></footer></div><script type="application/json" id="hydration">{"url":"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON","doc":{"body":[{"type":"prose","value":{"id":null,"title":null,"isH3":false,"content":"<p>The <strong><code>JSON</code></strong> namespace object contains static methods for parsing values from and converting values to <a href=\"https://json.org/\" class=\"external\" target=\"_blank\">JavaScript Object Notation</a> (<a href=\"/en-US/docs/Glossary/JSON\">JSON</a>).</p>"}},{"type":"prose","value":{"id":"description","title":"Description","isH3":false,"content":"<p>Unlike most global objects, <code>JSON</code> is not a constructor. You cannot use it with the <a href=\"/en-US/docs/Web/JavaScript/Reference/Operators/new\"><code>new</code> operator</a> or invoke the <code>JSON</code> object as a function. All properties and methods of <code>JSON</code> are static (just like the <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math\"><code>Math</code></a> object).</p>"}},{"type":"prose","value":{"id":"javascript_and_json_differences","title":"JavaScript and JSON differences","isH3":true,"content":"<p>JSON is a syntax for serializing objects, arrays, numbers, strings, booleans, and <a href=\"/en-US/docs/Web/JavaScript/Reference/Operators/null\"><code>null</code></a>. It is based upon JavaScript syntax, but is distinct from JavaScript: most of JavaScript is <em>not</em> JSON. For example:</p>\n<dl>\n<dt id=\"objects_and_arrays\"><a href=\"#objects_and_arrays\">Objects and Arrays</a></dt>\n<dd>\n<p>Property names must be double-quoted strings; <a href=\"/en-US/docs/Web/JavaScript/Reference/Trailing_commas\">trailing commas</a> are forbidden.</p>\n</dd>\n<dt id=\"numbers\"><a href=\"#numbers\">Numbers</a></dt>\n<dd>\n<p>Leading zeros are prohibited. A decimal point must be followed by at least one digit. <code>NaN</code> and <code>Infinity</code> are unsupported.</p>\n</dd>\n</dl>\n<p>Any JSON text is a valid JavaScript expression, but only after the <a href=\"https://github.com/tc39/proposal-json-superset\" class=\"external\" target=\"_blank\">JSON superset</a> revision. Before the revision, U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR are allowed in string literals and property keys in JSON; but the same use in JavaScript string literals is a <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/SyntaxError\"><code>SyntaxError</code></a>.</p>\n<p>Other differences include allowing only double-quoted strings and no support for <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/undefined\"><code>undefined</code></a> or comments. For those who wish to use a more human-friendly configuration format based on JSON, there is <a href=\"https://json5.org/\" class=\"external\" target=\"_blank\">JSON5</a>, used by the Babel compiler, and the more commonly used <a href=\"https://en.wikipedia.org/wiki/YAML\" class=\"external\" target=\"_blank\">YAML</a>.</p>\n<p>The same text may represent different values in JavaScript object literals vs. JSON as well. For more information, see <a href=\"/en-US/docs/Web/JavaScript/Reference/Operators/Object_initializer#object_literal_syntax_vs._json\">Object literal syntax vs. JSON</a>.</p>"}},{"type":"prose","value":{"id":"full_json_grammar","title":"Full JSON grammar","isH3":true,"content":"<p>Valid JSON syntax is formally defined by the following grammar, expressed in <a href=\"https://en.wikipedia.org/wiki/Augmented_Backus%E2%80%93Naur_form\" class=\"external\" target=\"_blank\">ABNF</a>, and copied from <a href=\"https://datatracker.ietf.org/doc/html/rfc8259\" class=\"external\" target=\"_blank\">IETF JSON standard (RFC)</a>:</p>\n<pre class=\"brush: plain notranslate\">JSON-text = object / array\nbegin-array = ws %x5B ws ; [ left square bracket\nbegin-object = ws %x7B ws ; { left curly bracket\nend-array = ws %x5D ws ; ] right square bracket\nend-object = ws %x7D ws ; } right curly bracket\nname-separator = ws %x3A ws ; : colon\nvalue-separator = ws %x2C ws ; , comma\nws = *(\n %x20 / ; Space\n %x09 / ; Horizontal tab\n %x0A / ; Line feed or New line\n %x0D ; Carriage return\n )\nvalue = false / null / true / object / array / number / string\nfalse = %x66.61.6c.73.65 ; false\nnull = %x6e.75.6c.6c ; null\ntrue = %x74.72.75.65 ; true\nobject = begin-object [ member *( value-separator member ) ]\n end-object\nmember = string name-separator value\narray = begin-array [ value *( value-separator value ) ] end-array\nnumber = [ minus ] int [ frac ] [ exp ]\ndecimal-point = %x2E ; .\ndigit1-9 = %x31-39 ; 1-9\ne = %x65 / %x45 ; e E\nexp = e [ minus / plus ] 1*DIGIT\nfrac = decimal-point 1*DIGIT\nint = zero / ( digit1-9 *DIGIT )\nminus = %x2D ; -\nplus = %x2B ; +\nzero = %x30 ; 0\nstring = quotation-mark *char quotation-mark\nchar = unescaped /\n escape (\n %x22 / ; \" quotation mark U+0022\n %x5C / ; \\ reverse solidus U+005C\n %x2F / ; / solidus U+002F\n %x62 / ; b backspace U+0008\n %x66 / ; f form feed U+000C\n %x6E / ; n line feed U+000A\n %x72 / ; r carriage return U+000D\n %x74 / ; t tab U+0009\n %x75 4HEXDIG ) ; uXXXX U+XXXX\nescape = %x5C ; \\\nquotation-mark = %x22 ; \"\nunescaped = %x20-21 / %x23-5B / %x5D-10FFFF\nHEXDIG = DIGIT / %x41-46 / %x61-66 ; 0-9, A-F, or a-f\n ; HEXDIG equivalent to HEXDIG rule in [RFC5234]\nDIGIT = %x30-39 ; 0-9\n ; DIGIT equivalent to DIGIT rule in [RFC5234]\n</pre>\n<p>Insignificant <a href=\"/en-US/docs/Glossary/Whitespace\">whitespace</a> may be present anywhere except within a <code>JSONNumber</code> (numbers must contain no whitespace) or <code>JSONString</code> (where it is interpreted as the corresponding character in the string, or would cause an error). The tab (U+0009), carriage return (U+000D), line feed (U+000A), and space (U+0020) characters are the only valid whitespace characters.</p>"}},{"type":"prose","value":{"id":"static_properties","title":"Static properties","isH3":false,"content":"<dl>\n<dt id=\"jsonsymbol.tostringtag\"><a href=\"#jsonsymbol.tostringtag\"><code>JSON[Symbol.toStringTag]</code></a></dt>\n<dd>\n<p>The initial value of the <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag\"><code>[Symbol.toStringTag]</code></a> property is the string <code>\"JSON\"</code>. This property is used in <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/toString\"><code>Object.prototype.toString()</code></a>.</p>\n</dd>\n</dl>"}},{"type":"prose","value":{"id":"static_methods","title":"Static methods","isH3":false,"content":"<dl>\n<dt id=\"json.israwjson\"><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/isRawJSON\"><code>JSON.isRawJSON()</code></a></dt>\n<dd>\n<p>Tests whether a value is an object returned by <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/rawJSON\"><code>JSON.rawJSON()</code></a>.</p>\n</dd>\n<dt id=\"json.parse\"><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse\"><code>JSON.parse()</code></a></dt>\n<dd>\n<p>Parse a piece of string text as JSON, optionally transforming the produced value and its properties, and return the value.</p>\n</dd>\n<dt id=\"json.rawjson\"><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/rawJSON\"><code>JSON.rawJSON()</code></a></dt>\n<dd>\n<p>Creates a \"raw JSON\" object containing a piece of JSON text. When serialized to JSON, the raw JSON object is treated as if it is already a piece of JSON. This text is required to be valid JSON.</p>\n</dd>\n<dt id=\"json.stringify\"><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify\"><code>JSON.stringify()</code></a></dt>\n<dd>\n<p>Return a JSON string corresponding to the specified value, optionally including only certain properties or replacing property values in a user-defined manner.</p>\n</dd>\n</dl>"}},{"type":"prose","value":{"id":"examples","title":"Examples","isH3":false,"content":""}},{"type":"prose","value":{"id":"example_json","title":"Example JSON","isH3":true,"content":"<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">json</span></div><pre class=\"brush: json notranslate\"><code>{\n \"browsers\": {\n \"firefox\": {\n \"name\": \"Firefox\",\n \"pref_url\": \"about:config\",\n \"releases\": {\n \"1\": {\n \"release_date\": \"2004-11-09\",\n \"status\": \"retired\",\n \"engine\": \"Gecko\",\n \"engine_version\": \"1.7\"\n }\n }\n }\n }\n}\n</code></pre></div>\n<p>You can use the <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse\"><code>JSON.parse()</code></a> method to convert the above JSON string into a JavaScript object:</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const jsonText = `{\n \"browsers\": {\n \"firefox\": {\n \"name\": \"Firefox\",\n \"pref_url\": \"about:config\",\n \"releases\": {\n \"1\": {\n \"release_date\": \"2004-11-09\",\n \"status\": \"retired\",\n \"engine\": \"Gecko\",\n \"engine_version\": \"1.7\"\n }\n }\n }\n }\n}`;\n\nconsole.log(JSON.parse(jsonText));\n</code></pre></div>"}},{"type":"prose","value":{"id":"lossless_number_serialization","title":"Lossless number serialization","isH3":true,"content":"<p>JSON can contain number literals of arbitrary precision. However, it is not possible to represent all JSON numbers exactly in JavaScript, because JavaScript uses floating point representation which has a fixed precision. For example, <code>12345678901234567890 === 12345678901234567000</code> in JavaScript because they have the same floating point representation. This means there is no JavaScript number that corresponds precisely to the <code>12345678901234567890</code> JSON number.</p>\n<p>Let's assume you have a exact representation of some number (either via <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt\"><code>BigInt</code></a> or a custom library):</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const data = {\n // Using a BigInt here to store the exact value,\n // but it can also be a custom high-precision number library,\n // if the number might not be an integer.\n gross_gdp: 12345678901234567890n,\n};\n</code></pre></div>\n<p>You want to serialize it and then parse to the same exact number. There are several difficulties:</p>\n<ul>\n<li>On the serialization side, in order to obtain a number in JSON, you have to pass a number to <code>JSON.stringify</code>, either via the <code>replacer</code> function or via the <code>toJSON</code> method. But, in either case, you have already lost precision during number conversion. If you pass a string to <code>JSON.stringify</code>, it will be serialized as a string, not a number.</li>\n<li>On the parsing side, not all numbers can be represented exactly. For example, <code>JSON.parse(\"12345678901234567890\")</code> returns <code>12345678901234568000</code> because the number is rounded to the nearest representable number. Even if you use a <code>reviver</code> function, the number will already be rounded before the <code>reviver</code> function is called.</li>\n</ul>\n<p>There are, in general, two ways to ensure that numbers are losslessly converted to JSON and parsed back: one involves a JSON number, another involves a JSON string. JSON is a <em>communication format</em>, so if you use JSON, you are likely communicating with another system (HTTP request, storing in database, etc.). The best solution to choose depends on the recipient system.</p>\n<h4 id=\"using_json_strings\">Using JSON strings</h4>\n<p>If the recipient system does not have same JSON-handling capabilities as JavaScript, and does not support high precision numbers, you may want to serialize the number as a string, and then handle it as a string on the recipient side. This is also the only option in older JavaScript.</p>\n<p>To specify how custom data types (including <code>BigInt</code>) should be serialized to JSON, either add a <code>toJSON</code> method to your data type, or use the <code>replacer</code> function of <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify\"><code>JSON.stringify()</code></a>.</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>// Using toJSON() method\nBigInt.prototype.toJSON = function () {\n return this.toString();\n};\nconst str1 = JSON.stringify(data);\n\n// Using JSON.stringify() with replacer\nconst str2 = JSON.stringify(data, (key, value) => {\n if (key === \"gross_gdp\") {\n return value.toString();\n }\n return value;\n});\n</code></pre></div>\n<p>In either case, the JSON text will look like <code>{\"gross_gdp\":\"12345678901234567890\"}</code>, where the value is a string, not a number. Then, on the recipient side, you can parse the JSON and handle the string.</p>\n<h4 id=\"using_json_numbers\">Using JSON numbers</h4>\n<p>If the recipient of this message natively supports high precision numbers (such as Python integers), passing numbers as JSON numbers is obviously better, because they can directly parse to the high precision type instead of parsing a string from JSON, and then parsing a number from the string. In JavaScript, you can serialize arbitrary data types to JSON numbers without producing a number value first (resulting in loss of precision) by using <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/rawJSON\"><code>JSON.rawJSON()</code></a> to precisely specify what the JSON source text should be.</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>// Using toJSON() method\nBigInt.prototype.toJSON = function () {\n return JSON.rawJSON(this.toString());\n};\nconst str1 = JSON.stringify(data);\n\n// Using JSON.stringify() with replacer\nconst str2 = JSON.stringify(data, (key, value) => {\n if (key === \"gross_gdp\") {\n return JSON.rawJSON(value.toString());\n }\n return value;\n});\n</code></pre></div>\n<p>The text passed to <code>JSON.rawJSON</code> is treated as if it is already a piece of JSON, so it won't be serialized again as a string. Therefore, the JSON text will look like <code>{\"gross_gdp\":12345678901234567890}</code>, where the value is a number. This JSON can then be parsed by the recipient without any extra processing, provided that the recipient system does not have the same precision limitations as JavaScript.</p>\n<p>When parsing JSON containing high-precision numbers in JavaScript, take extra care because when <code>JSON.parse()</code> invokes the <code>reviver</code> function, the value you receive is already parsed (and has lost precision). You can use the <code>context.source</code> parameter of the <a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse\"><code>JSON.parse()</code></a> <code>reviver</code> function to re-parse the number yourself.</p>\n<div class=\"code-example\"><div class=\"example-header\"><span class=\"language-name\">js</span></div><pre class=\"brush: js notranslate\"><code>const parsedData = JSON.parse(str, (key, value, context) => {\n if (key === \"gross_gdp\") {\n // Or use the constructor of your custom high-precision number library\n return BigInt(context.source);\n }\n return value;\n});\n// { gross_gdp: 12345678901234567890n }\n</code></pre></div>"}},{"type":"specifications","value":{"id":"specifications","title":"Specifications","isH3":false,"specifications":[{"bcdSpecificationURL":"https://tc39.es/ecma262/multipage/structured-data.html#sec-json-object","title":"ECMAScript® 2025 Language Specification"}],"query":"javascript.builtins.JSON"}},{"type":"browser_compatibility","value":{"id":"browser_compatibility","title":"Browser compatibility","isH3":false,"query":"javascript.builtins.JSON"}},{"type":"prose","value":{"id":"see_also","title":"See also","isH3":false,"content":"<ul>\n<li><a href=\"https://json-diff.com/\" class=\"external\" target=\"_blank\">JSON Diff</a></li>\n<li><a href=\"https://jsonbeautifier.org/\" class=\"external\" target=\"_blank\">JSON Beautifier/editor</a></li>\n<li><a href=\"https://jsonparser.org/\" class=\"external\" target=\"_blank\">JSON Parser</a></li>\n<li><a href=\"https://tools.learningcontainer.com/json-validator/\" class=\"external\" target=\"_blank\">JSON Validator</a></li>\n</ul>"}}],"isActive":true,"isMarkdown":true,"isTranslated":false,"locale":"en-US","mdn_url":"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON","modified":"2025-01-20T22:28:20.000Z","native":"English (US)","noIndexing":false,"other_translations":[{"locale":"de","title":"JSON","native":"Deutsch"},{"locale":"es","title":"JSON","native":"Español"},{"locale":"fr","title":"JSON","native":"Français"},{"locale":"ja","title":"JSON","native":"日本語"},{"locale":"ko","title":"JSON","native":"한국어"},{"locale":"pt-BR","title":"JSON","native":"Português (do Brasil)"},{"locale":"ru","title":"JSON","native":"Русский"},{"locale":"zh-CN","title":"JSON","native":"中文 (简体)"},{"locale":"zh-TW","title":"JSON","native":"正體中文 (繁體)"}],"pageTitle":"JSON - JavaScript | MDN","parents":[{"uri":"/en-US/docs/Web","title":"References"},{"uri":"/en-US/docs/Web/JavaScript","title":"JavaScript"},{"uri":"/en-US/docs/Web/JavaScript/Reference","title":"Reference"},{"uri":"/en-US/docs/Web/JavaScript/Reference/Global_Objects","title":"Standard built-in objects"},{"uri":"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON","title":"JSON"}],"popularity":null,"short_title":"JSON","sidebarHTML":"<ol><li class=\"section\"><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects\">Standard built-in objects</a></li><li class=\"section\"><em><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON\" aria-current=\"page\"><code>JSON</code></a></em></li><li class=\"toggle\"><details open=\"\"><summary>Static methods</summary><ol><li><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/isRawJSON\"><code>JSON.isRawJSON()</code></a></li><li><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse\"><code>JSON.parse()</code></a></li><li><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/rawJSON\"><code>JSON.rawJSON()</code></a></li><li><a href=\"/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify\"><code>JSON.stringify()</code></a></li></ol></details></li></ol>","source":{"folder":"en-us/web/javascript/reference/global_objects/json","github_url":"https://github.com/mdn/content/blob/main/files/en-us/web/javascript/reference/global_objects/json/index.md","last_commit_url":"https://github.com/mdn/content/commit/a4e9bce1e8bac1b845b32536e0e44f335233eab6","filename":"index.md"},"summary":"The JSON namespace object contains static methods for parsing values from and converting values to JavaScript Object Notation (JSON).","title":"JSON","toc":[{"text":"Description","id":"description"},{"text":"Static properties","id":"static_properties"},{"text":"Static methods","id":"static_methods"},{"text":"Examples","id":"examples"},{"text":"Specifications","id":"specifications"},{"text":"Browser compatibility","id":"browser_compatibility"},{"text":"See also","id":"see_also"}],"baseline":{"baseline":"high","baseline_low_date":"2015-07-29","baseline_high_date":"2018-01-29","support":{"chrome":"3","chrome_android":"18","edge":"12","firefox":"3.5","firefox_android":"4","safari":"4","safari_ios":"4"},"asterisk":true},"browserCompat":["javascript.builtins.JSON"],"pageType":"javascript-namespace"}}</script></body></html>