# jsx-a11y/alt-text 💼 This rule is enabled in the following configs: ☑️ `recommended`, 🔒 `strict`. Enforce that all elements that require alternative text have meaningful information to relay back to the end user. This is a critical component of accessibility for screen reader users in order for them to understand the content's purpose on the page. By default, this rule checks for alternative text on the following elements: ``, ``, ``, and ``. ## How to resolve ### `` An `` must have the `alt` prop set with meaningful text or as an empty string to indicate that it is an image for decoration. For images that are being used as icons for a button or control, the `alt` prop should be set to an empty string (`alt=""`). ```jsx ``` The content of an `alt` attribute is used to calculate the accessible label of an element, whereas the text content is used to produce a label for the element. For this reason, adding a label to an icon can produce a confusing or duplicated label on a control that already has appropriate text content. ### `` Add alternative text to all embedded `` elements using either inner text, setting the `title` prop, or using the `aria-label` or `aria-labelledby` props. ### `` All `` elements must have a non-empty `alt` prop set with a meaningful description of the image or have the `aria-label` or `aria-labelledby` props set. ### `` All clickable `` elements within an image map have an `alt`, `aria-label` or `aria-labelledby` prop that describes the purpose of the link. ## Rule options This rule takes one optional object argument of type object: ```json { "rules": { "jsx-a11y/alt-text": [ 2, { "elements": [ "img", "object", "area", "input[type=\"image\"]" ], "img": ["Image"], "object": ["Object"], "area": ["Area"], "input[type=\"image\"]": ["InputImage"] }], } } ``` The `elements` option is a whitelist for DOM elements to check for alternative text. If an element is removed from the default set of elements (noted above), any custom components for that component will also be ignored. In order to indicate any custom wrapper components that should be checked, you can map the DOM element to an array of JSX custom components. This is a good use case when you have a wrapper component that simply renders an `img` element, for instance (like in React): ```jsx // Image.js const Image = props => { const { alt, ...otherProps } = props; return ( {alt} ); } ... // Header.js (for example) ... return (
Logo
); ``` Note that passing props as spread attribute without explicitly the necessary accessibility props defined will cause this rule to fail. Explicitly pass down the set of props needed for rule to pass. Use `Image` component above as a reference for destructuring and applying the prop. **It is a good thing to explicitly pass props that you expect to be passed for self-documentation.** For example: #### Bad ```jsx function Foo(props) { return } ``` #### Good ```jsx function Foo({ alt, ...props}) { return {alt} } // OR function Foo(props) { const { alt, ...otherProps } = props; return {alt} } ``` ### Succeed ```jsx Foo eating a sandwich. {"Foo {altText} {`${person} Meaningful description This is descriptive! ``` ### Fail ```jsx // Has no value {undefined} // Has no value {`${undefined}`} // Has no value // Avoid ARIA if it can be achieved without // Avoid ARIA if it can be achieved without ``` ## Accessibility guidelines - [WCAG 1.1.1](https://www.w3.org/WAI/WCAG21/Understanding/non-text-content.html) ### Resources - [axe-core, object-alt](https://dequeuniversity.com/rules/axe/3.2/object-alt) - [axe-core, image-alt](https://dequeuniversity.com/rules/axe/3.2/image-alt) - [axe-core, input-image-alt](https://dequeuniversity.com/rules/axe/3.2/input-image-alt) - [axe-core, area-alt](https://dequeuniversity.com/rules/axe/3.2/area-alt)