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C37: Using CSS max-width and height to fit images | WAI | W3C
<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml" lang="en"><head> <title>C37: Using CSS max-width and height to fit images | WAI | W3C</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://w3.org/WAI/assets/css/style.css"> <link rel="stylesheet" href="../base.css"> </head> <body dir="ltr"> <a href="#main" class="button button--skip-link">Skip to content</a> <div class="minimal-header-container default-grid"> <header class="minimal-header" id="site-header"> <div class="minimal-header-name"> <a href="https://www.w3.org/WAI/WCAG22/Techniques/">WCAG 2.2 Techniques</a> </div> <div class="minimal-header-subtitle">Examples of ways to meet WCAG; not required</div> <a class="minimal-header-link" href="https://www.w3.org/WAI/WCAG22/Techniques/about">About WCAG Techniques</a> <div class="minimal-header-logo"> <a href="http://w3.org/" aria-label="W3C"> <svg xmlns="http://www.w3.org/2000/svg" height="2em" viewBox="0 0 91.968 44"> 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45.5h-1.817l-3.779-14.277h1.875l2.217 8.72c.3 1.14.527 2.272.684 3.399.143-1.068.397-2.237.761-3.506l2.52-8.613h1.855l2.627 8.681c.339 1.127.6 2.272.781 3.438.105-.899.336-2.038.694-3.418l2.207-8.701h1.875zm14.57 0l-1.718-4.424h-5.664l-1.7 4.424h-1.816l5.576-14.336h1.621l5.567 14.336zm-2.256-6.016l-1.601-4.326-.684-2.138c-.195.78-.4 1.494-.615 2.138l-1.621 4.326zm10.098 6.016h-5.156v-1.035l1.68-.381V32.658l-1.68-.4v-1.035h5.156v1.035l-1.68.4v11.426l1.68.38z"></path> </g> </g> </svg> </a> </div> </header> </div> <div class="default-grid with-gap leftcol"> <aside class="box nav-hack sidebar standalone-resource__sidebar"> <header class="box-h">Page Contents</header> <div class="box-i"> <nav aria-label="page contents" class="navtoc"> <ul><li><a href="#technique">About this Technique</a></li> <li><a href="#description">Description</a></li> <li><a href="#examples">Examples</a></li> <li><a href="#tests">Tests</a></li> </ul> </nav> </div> </aside> <main id="main" class="standalone-resource__main"> <h1><span>Technique C37:</span>Using <abbr title="Cascading Style Sheets">CSS</abbr> <code class="language-css">max-width</code> and <code class="language-css">height</code> to fit images</h1> <section id="technique" class="box"> <h2 class="box-h box-h-icon">About this Technique</h2> <div class="box-i"> <p> This technique relates to <a href="https://www.w3.org/WAI/WCAG22/Understanding/reflow">1.4.10: Reflow</a> (<strong>Advisory</strong>).</p> <p>This technique applies to <abbr title="Cascading Style Sheets">CSS</abbr> and <abbr title="HyperText Markup Language">HTML</abbr>.</p> </div> </section> <section id="description"> <h2>Description</h2> <p>The objective of this technique is to be able to present images without introducing a horizontal scroll bar at a width equivalent to 320 CSS pixels, or a vertical scroll bar at a height equivalent to 256 CSS pixels for content intended to scroll horizontally. This is done by using CSS <code class="language-css">max-width</code> and <code class="language-css">height</code> property techniques that adapt to the available space and keep the original dimensions of the image.</p> <p>Responsive layouts can add or remove columns or layout blocks, and each part of the layout can be wider or smaller at different points. This technique ensures images do not break out of their layout area, including in one-column layouts where it would cause scrolling.</p> <p>The basic principles of fitting images are to:</p> <ol> <li>Define the <code class="language-css">max-width</code> property for images, and;</li> <li>Define the <code class="language-css">height</code> property for images, so they enlarge or shrink in the available space and respond to zoom levels.</li> </ol> <p>All images require design finesse by making sure the original size fits the biggest size of the available spaces to achieve good-looking results at a wide range of viewport sizes and zoom levels.</p> </section> <section id="examples"> <h2>Examples</h2> <section class="example" id="example-1-fitting-images-in-html-and-css"> <h3>Example 1: Fitting images in HTML and CSS</h3> <p>The following simple example uses HTML and CSS to create a fitting image. The layout regions adjust their size as the viewport is adjusted. The images subsequently adjust their size to fit within the layout region containers.</p> <p>The zoom level can be increased to 400% without requiring scrolling in more than one direction. This particular example uses a percent size for the <code class="language-css">max-width</code> and auto size for the <code class="language-css">height</code> of the image to remain the original dimensions.</p> <pre xml:space="preserve"><code class="language-html"><style> .img-responsive { max-width: 100%; } </style> <div class="panel"> <img alt="" class="img-responsive" src="..."> ... </div></code></pre> <p class="working-example">Working example: <a href="../../working-examples/css-fitting-images/">Using Fitting Images for Reflow</a></p> </section> </section> <section id="tests"> <h2>Tests</h2> <section class="test-procedure" id="procedure"> <h3>Procedure</h3> <ol> <li>Display the web page in a user agent capable of 400% zoom and set the viewport dimensions (in CSS pixels) to 1280 wide and 1024 high.</li> <li>Zoom in by 400%.</li> <li>For content read horizontally, check that all images fit in their available space without horizontal scrolling.</li> <li>For content read vertically, check that all images fit in their available space without vertical scrolling.</li> </ol> <div class="note"> <p class="note-title marker">Note</p> <p>If the browser is not capable of zooming to 400%, you can reduce the width of the browser proportionally. For example, at 300% zoom the viewport should be sized to 960px wide.</p> </div> </section> <section class="test-results" id="expected-results"> <h3>Expected Results</h3> <p>#3 and #4 are true.</p> </section> </section> <a class="button button-backtotop" href="#top"> <span> <svg focusable="false" aria-hidden="true" class="icon-arrow-up " viewBox="0 0 26 28"> <path d="M25.172 15.172c0 0.531-0.219 1.031-0.578 1.406l-1.172 1.172c-0.375 0.375-0.891 0.594-1.422 0.594s-1.047-0.219-1.406-0.594l-4.594-4.578v11c0 1.125-0.938 1.828-2 1.828h-2c-1.062 0-2-0.703-2-1.828v-11l-4.594 4.578c-0.359 0.375-0.875 0.594-1.406 0.594s-1.047-0.219-1.406-0.594l-1.172-1.172c-0.375-0.375-0.594-0.875-0.594-1.406s0.219-1.047 0.594-1.422l10.172-10.172c0.359-0.375 0.875-0.578 1.406-0.578s1.047 0.203 1.422 0.578l10.172 10.172c0.359 0.375 0.578 0.891 0.578 1.422z"></path> </svg> Back to Top </span> </a> </main> <aside class="box box-icon box-space-above" id="helpimprove" style="grid-column: 2 / 8; grid-row: 3"> <header class="box-h box-h-icon box-h-space-above box-h-icon"> <svg focusable="false" aria-hidden="true" class="icon-comments" viewBox="0 0 28 28"> <path d="M22 12c0 4.422-4.922 8-11 8-0.953 0-1.875-0.094-2.75-0.25-1.297 0.922-2.766 1.594-4.344 2-0.422 0.109-0.875 0.187-1.344 0.25h-0.047c-0.234 0-0.453-0.187-0.5-0.453v0c-0.063-0.297 0.141-0.484 0.313-0.688 0.609-0.688 1.297-1.297 1.828-2.594-2.531-1.469-4.156-3.734-4.156-6.266 0-4.422 4.922-8 11-8s11 3.578 11 8zM28 16c0 2.547-1.625 4.797-4.156 6.266 0.531 1.297 1.219 1.906 1.828 2.594 0.172 0.203 0.375 0.391 0.313 0.688v0c-0.063 0.281-0.297 0.484-0.547 0.453-0.469-0.063-0.922-0.141-1.344-0.25-1.578-0.406-3.047-1.078-4.344-2-0.875 0.156-1.797 0.25-2.75 0.25-2.828 0-5.422-0.781-7.375-2.063 0.453 0.031 0.922 0.063 1.375 0.063 3.359 0 6.531-0.969 8.953-2.719 2.609-1.906 4.047-4.484 4.047-7.281 0-0.812-0.125-1.609-0.359-2.375 2.641 1.453 4.359 3.766 4.359 6.375z"></path> </svg> <h2>Help improve this page</h2> </header> <div class="box-i"> <p>Please share your ideas, suggestions, or comments via e-mail to the publicly-archived list <a href="mailto:public-agwg-comments@w3.org?subject=%5BUnderstanding%20and%20Techniques%20Feedback%5D">public-agwg-comments@w3.org</a> or via GitHub</p> <div class="button-group"> <a href="mailto:public-agwg-comments@w3.org?subject=%5BUnderstanding%20and%20Techniques%20Feedback%5D" class="button"><span>E-mail</span></a> <a href="https://github.com/w3c/wcag/issues/" class="button"><span>Fork & Edit on GitHub</span></a> <a href="https://github.com/w3c/wcag/issues/new" class="button"><span>New GitHub Issue</span></a> </div> </div> </aside> </div> <footer id="wai-site-footer" class="page-footer default-grid" aria-label="Page"> <div class="inner" style="grid-column: 2 / 8"> <p><strong>Date:</strong> Updated 02 April 2024.</p> <p><strong>Developed by</strong> <a href="https://www.w3.org/groups/wg/ag/participants">Accessibility Guidelines Working Group (AG WG) Participants</a> (Co-Chairs: Alastair Campbell, Charles Adams, Rachael Bradley Montgomery. 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