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<!DOCTYPE html><html lang="en"><head><meta charSet="utf-8"/><title>API – SWR</title><meta name="robots" content="index,follow"/><meta property="og:title" content="API – SWR"/><meta name="theme-color" content="#111" media="(prefers-color-scheme: dark)"/><meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover"/><style> :root { --nextra-primary-hue: 212deg; --nextra-navbar-height: 4rem; --nextra-menu-height: 3.75rem; --nextra-banner-height: 2.5rem; } .dark { --nextra-primary-hue: 204deg; } </style><link rel="apple-touch-icon" sizes="180x180" href="/favicon/apple-touch-icon.png"/><link rel="icon" type="image/png" sizes="32x32" href="/favicon/favicon-32x32.png"/><link rel="icon" type="image/png" sizes="16x16" href="/favicon/favicon-16x16.png"/><link rel="icon" type="image/svg+xml" href="/favicon/favicon.svg"/><link rel="manifest" href="/favicon/site.webmanifest"/><link rel="mask-icon" href="/favicon/safari-pinned-tab.svg" color="#000000"/><meta http-equiv="Content-Language" content="en-US, zh-CN, es-ES, fr-FR, pt-BR, ja, ko, ru"/><meta name="msapplication-TileColor" content="#ffffff"/><meta name="apple-mobile-web-app-title" content="SWR"/><meta name="description" content="SWR is a React Hooks library for data fetching. SWR first returns the data from cache (stale), then sends the fetch request (revalidate), and finally comes with the up-to-date data again."/><meta name="twitter:card" content="summary_large_image"/><meta name="twitter:site" content="@vercel"/><meta name="twitter:image" content="https://swr-card.vercel.app/?title=API"/><meta property="og:title" content="API – SWR"/><meta property="og:description" content="SWR is a React Hooks library for data fetching. 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class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/getting-started">Getting Started</a></li><li class="nx-flex nx-flex-col nx-gap-1 active"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-bg-primary-100 nx-font-semibold nx-text-primary-800 dark:nx-bg-primary-400/10 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[-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/data-fetching">Data Fetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/revalidation">Auto Revalidation</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/arguments">Arguments</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/mutation">Mutation & Revalidation</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/error-handling">Error Handling</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/conditional-fetching">Conditional Data Fetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/pagination">Pagination</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/subscription">Subscription</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/prefetching">Prefetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/with-nextjs">Next.js SSG and SSR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/typescript">TypeScript</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/suspense">Suspense</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/middleware">Middleware</a></li><li class="open"><button class="nx-items-center nx-justify-between nx-gap-2 nx-text-left nx-w-full nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Advanced<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180 ltr:nx-rotate-90 rtl:nx-rotate-[-270deg]"></path></svg></button><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-100 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/understanding">Understanding SWR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/cache">Cache</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/performance">Performance</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/react-native">React Native</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/devtools">Developer Tools</a></li></ul></div></div></li><li class="nx-flex nx-flex-col nx-gap-1"><a href="https://github.com/vercel/swr/releases" target="_blank" rel="noreferrer" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Change Log<span class="nx-sr-only"> (opens in a new tab)</span></a></li></ul></div></div><ul class="nx-flex nx-flex-col nx-gap-1 md:nx-hidden"><li class="open"><button class="nx-items-center nx-justify-between nx-gap-2 nx-text-left nx-w-full nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Docs<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180 ltr:nx-rotate-90 rtl:nx-rotate-[-270deg]"></path></svg></button><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-100 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/getting-started">Getting Started</a></li><li class="nx-flex nx-flex-col nx-gap-1 active"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-bg-primary-100 nx-font-semibold nx-text-primary-800 dark:nx-bg-primary-400/10 dark:nx-text-primary-600 contrast-more:nx-border-primary-500 contrast-more:dark:nx-border-primary-500" href="/docs/api">API</a><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li><a href="#parameters" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Parameters</a></li><li><a href="#return-values" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Return Values</a></li><li><a href="#options" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Options</a></li></ul></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/global-configuration">Global Configuration</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/data-fetching">Data Fetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/revalidation">Auto Revalidation</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/arguments">Arguments</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/mutation">Mutation & Revalidation</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/error-handling">Error Handling</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/conditional-fetching">Conditional Data Fetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/pagination">Pagination</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/subscription">Subscription</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/prefetching">Prefetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/with-nextjs">Next.js SSG and SSR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/typescript">TypeScript</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/suspense">Suspense</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/middleware">Middleware</a></li><li class=""><button class="nx-items-center nx-justify-between nx-gap-2 nx-text-left nx-w-full nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Advanced<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180"></path></svg></button><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none" style="height:0"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-0 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/understanding">Understanding SWR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/cache">Cache</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/performance">Performance</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/react-native">React Native</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/devtools">Developer Tools</a></li></ul></div></div></li><li class="nx-flex nx-flex-col nx-gap-1"><a href="https://github.com/vercel/swr/releases" target="_blank" rel="noreferrer" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Change Log<span class="nx-sr-only"> (opens in a new tab)</span></a></li></ul></div></div></li><li class="open"><button class="nx-items-center nx-justify-between nx-gap-2 nx-text-left nx-w-full nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Examples<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180 ltr:nx-rotate-90 rtl:nx-rotate-[-270deg]"></path></svg></button><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-100 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/basic">Basic Usage</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/auth">Authentication</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/optimistic-ui">Optimistic UI</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/infinite-loading">Infinite Loading</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/error-handling">Error Handling</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/ssr">Next.js SSR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/subscription">Subscription</a></li></ul></div></div></li><li class="open"><a class="nx-items-center nx-justify-between nx-gap-2 nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/blog">Blog<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180 ltr:nx-rotate-90 rtl:nx-rotate-[-270deg]"></path></svg></a><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-100 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/blog/swr-v2">Announcing SWR 2.0</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/blog/swr-v1">Announcing SWR 1.0</a></li></ul></div></div></li></ul></div><div class="nx-sticky nx-bottom-0 nx-bg-white dark:nx-bg-dark nx-mx-4 nx-py-4 nx-shadow-[0_-12px_16px_#fff] nx-flex nx-items-center nx-gap-2 dark:nx-border-neutral-800 dark:nx-shadow-[0_-12px_16px_#111] contrast-more:nx-border-neutral-400 contrast-more:nx-shadow-none contrast-more:dark:nx-shadow-none nx-justify-end nx-border-t" data-toggle-animation="off"><button title="Change language" class="nx-h-7 nx-rounded-md nx-px-2 nx-text-left nx-text-xs nx-font-medium nx-text-gray-600 nx-transition-colors dark:nx-text-gray-400 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 nx-grow" id="headlessui-listbox-button-:R2fjcm:" type="button" aria-haspopup="listbox" aria-expanded="false" data-headlessui-state=""><span class="nx-flex nx-items-center 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[hyphens:auto] nx-max-h-[calc(100vh-var(--nextra-navbar-height)-env(safe-area-inset-bottom))] ltr:-nx-mr-4 rtl:-nx-ml-4"><p class="nx-mb-4 nx-font-semibold nx-tracking-tight">On This Page</p><ul><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#parameters" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Parameters</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#return-values" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Return Values</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#options" class="nx-font-semibold nx-inline-block 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Give us feedback →<span class="nx-sr-only"> (opens in a new tab)</span></a><a class="nx-text-xs nx-font-medium nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-100 contrast-more:nx-text-gray-800 contrast-more:dark:nx-text-gray-50" href="https://github.com/vercel/swr-site/blob/main/pages/docs/api.en-US.mdx">Edit this page on GitHub →</a></div></div></nav><div id="reach-skip-nav"></div><article class="nx-w-full nx-break-words nextra-content nx-flex nx-min-h-[calc(100vh-var(--nextra-navbar-height))] nx-min-w-0 nx-justify-center nx-pb-8 nx-pr-[calc(env(safe-area-inset-right)-1.5rem)]"><main class="nx-w-full nx-min-w-0 nx-max-w-6xl nx-px-6 nx-pt-4 md:nx-px-12"><div class="nextra-breadcrumb nx-mt-1.5 nx-flex nx-items-center nx-gap-1 nx-overflow-hidden nx-text-sm nx-text-gray-500 contrast-more:nx-text-current"><div class="nx-whitespace-nowrap nx-transition-colors nx-min-w-[24px] nx-overflow-hidden nx-text-ellipsis" title="Docs">Docs</div><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-w-3.5 nx-shrink-0"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7"></path></svg><div class="nx-whitespace-nowrap nx-transition-colors nx-font-medium nx-text-gray-700 contrast-more:nx-font-bold contrast-more:nx-text-current dark:nx-text-gray-400 contrast-more:dark:nx-text-current" title="API">API</div></div><h1 class="nx-mt-2 nx-text-4xl nx-font-bold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100">API</h1> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-font-medium nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4 " data-language="js" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr" data-language="js" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">error</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">isLoading</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">isValidating</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">mutate</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWR</span><span style="color:var(--shiki-color-text)">(key</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> fetcher</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> options)</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 " title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Parameters<span class="nx-absolute -nx-mt-20" id="parameters"></span><a href="#parameters" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">key</code>: a unique key string for the request (or a function / array / null) <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/arguments">(details)</a>, <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/conditional-fetching">(advanced usage)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">fetcher</code>: (<em>optional</em>) a Promise-returning function to fetch your data <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/data-fetching">(details)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">options</code>: (<em>optional</em>) an object of options for this SWR hook</li> </ul> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Return Values<span class="nx-absolute -nx-mt-20" id="return-values"></span><a href="#return-values" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">data</code>: data for the given key resolved by <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">fetcher</code> (or undefined if not loaded)</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">error</code>: error thrown by <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">fetcher</code> (or undefined)</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">isLoading</code>: if there's an ongoing request and no "loaded data". Fallback data and previous data are not considered "loaded data"</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">isValidating</code>: if there's a request or revalidation loading</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">mutate(data?, options?)</code>: function to mutate the cached data <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/mutation">(details)</a></li> </ul> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">More information can be found <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/advanced/understanding">here</a>.</p> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Options<span class="nx-absolute -nx-mt-20" id="options"></span><a href="#options" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">suspense = false</code>: enable React Suspense mode <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/suspense">(details)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">fetcher(args)</code>: the fetcher function</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">revalidateIfStale = true</code>: automatically revalidate even if there is stale data <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/revalidation#disable-automatic-revalidations">(details)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">revalidateOnMount</code>: enable or disable automatic revalidation when component is mounted <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/revalidation#revalidate-on-mount">(details)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">revalidateOnFocus = true</code>: automatically revalidate when window gets focused <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/revalidation">(details)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">revalidateOnReconnect = true</code>: automatically revalidate when the browser regains a network connection (via <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">navigator.onLine</code>) <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/revalidation">(details)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">refreshInterval</code> <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/revalidation">(details)</a>: <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2">Disabled by default: <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">refreshInterval = 0</code></li> <li class="nx-my-2">If set to a number, polling interval in milliseconds</li> <li class="nx-my-2">If set to a function, the function will receive the latest data and should return the interval in milliseconds</li> </ul> </li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">refreshWhenHidden = false</code>: polling when the window is invisible (if <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">refreshInterval</code> is enabled)</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">refreshWhenOffline = false</code>: polling when the browser is offline (determined by <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">navigator.onLine</code>)</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">shouldRetryOnError = true</code>: retry when fetcher has an error</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">dedupingInterval = 2000</code>: dedupe requests with the same key in this time span in milliseconds</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">focusThrottleInterval = 5000</code>: only revalidate once during a time span in milliseconds</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">loadingTimeout = 3000</code>: timeout to trigger the onLoadingSlow event in milliseconds</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">errorRetryInterval = 5000</code>: error retry interval in milliseconds</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">errorRetryCount</code>: max error retry count</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">fallback</code>: a key-value object of multiple fallback data <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/with-nextjs">(example)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">fallbackData</code>: initial data to be returned (note: This is per-hook)</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">keepPreviousData = false</code>: return the previous key's data until the new data has been loaded <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/advanced/understanding#return-previous-data-for-better-ux">(details)</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">onLoadingSlow(key, config)</code>: callback function when a request takes too long to load (see <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">loadingTimeout</code>)</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">onSuccess(data, key, config)</code>: callback function when a request finishes successfully</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">onError(err, key, config)</code>: callback function when a request returns an error</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">onErrorRetry(err, key, config, revalidate, revalidateOps)</code>: handler for error retry</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">onDiscarded(key)</code>: callback function when a request is ignored due to race conditions</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">compare(a, b)</code>: comparison function used to detect when returned data has changed, to avoid spurious rerenders. By default, <a href="https://github.com/shuding/stable-hash" target="_blank" rel="noreferrer" class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]">stable-hash<span class="nx-sr-only"> (opens in a new tab)</span></a> is used.</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">isPaused()</code>: function to detect whether pause revalidations, will ignore fetched data and errors when it returns <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">true</code>. Returns <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">false</code> by default.</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10 " dir="ltr">use</code>: array of middleware functions <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/middleware">(details)</a></li> </ul> <div class="nextra-callout nx-overflow-x-auto nx-mt-6 nx-flex nx-rounded-lg nx-border nx-py-2 ltr:nx-pr-4 rtl:nx-pl-4 contrast-more:nx-border-current contrast-more:dark:nx-border-current nx-border-orange-100 nx-bg-orange-50 nx-text-orange-800 dark:nx-border-orange-400/30 dark:nx-bg-orange-400/20 dark:nx-text-orange-300"><div class="nx-select-none nx-text-xl ltr:nx-pl-3 ltr:nx-pr-2 rtl:nx-pr-3 rtl:nx-pl-2" style="font-family:"Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol"">💡</div><div class="nx-w-full nx-min-w-0 nx-leading-7"><p class="nx-mt-6 nx-leading-7 first:nx-mt-0">When under a slow network (2G, <= 70Kbps), <code>errorRetryInterval</code> will be 10s, and  <code>loadingTimeout</code> will be 5s by default.</p></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">You can also use <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/global-configuration">global configuration</a> to provide default options.</p><div class="nx-mt-16"></div><div class="nx-mb-8 nx-flex nx-items-center nx-border-t nx-pt-8 dark:nx-border-neutral-800 contrast-more:nx-border-neutral-400 dark:contrast-more:nx-border-neutral-400 print:nx-hidden"><a title="Getting Started" class="nx-flex nx-max-w-[50%] nx-items-center nx-gap-1 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