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Accessibility Guides for EN 301 549
Learn how to identify and fix common accessibility issues flagged by Axe Core — so your pages are inclusive and usable for everyone. Also check our HTML Validation Guides.
When a button lacks an accessible name, assistive technologies like screen readers can only announce it generically — for example, as "button" — with no indication of its purpose. This is a critical barrier for people who are blind or deafblind, as they rely entirely on programmatically determined names to understand and interact with interface controls. A sighted user might infer a button's purpose from an icon or visual context, but without a text-based name, that information is completely lost to assistive technology users.
This rule maps to WCAG 2.0, 2.1, and 2.2 Success Criterion 4.1.2: Name, Role, Value (Level A), which requires that all user interface components have a name that can be programmatically determined. It is also covered by Section 508, EN 301 549 (9.4.1.2), and Trusted Tester guidelines, which require that the purpose of every link and button be determinable from its accessible name, description, or context.
How to fix it
Ensure every <button> element or element with role="button" has an accessible name through one of these methods:
- Visible text content inside the button element.
- A non-empty
aria-labelattribute that describes the button's purpose. - An
aria-labelledbyattribute that references an element containing visible, non-empty text. - A
titleattribute (use as a last resort, sincetitletooltips are inconsistently exposed across devices).
If a button is purely decorative and should be hidden from assistive technologies, you can assign role="presentation" or role="none" and remove it from the tab order with tabindex="-1". However, this is rare for interactive buttons.
Common mistakes to avoid
- Leaving a
<button>element completely empty. - Using only a
valueattribute on a<button>— unlike<input>elements, thevalueattribute on<button>does not provide an accessible name. - Setting
aria-labelto an empty string (aria-label=""). - Pointing
aria-labelledbyto an element that doesn't exist or contains no text. - Using only an icon or image inside a button without providing alternative text.
Examples
Incorrect: empty button
<button id="search"></button>
A screen reader announces this as "button" with no indication of its purpose.
Incorrect: button with only a value attribute
<button id="submit" value="Submit"></button>
The value attribute does not set the accessible name for <button> elements.
Incorrect: empty aria-label
<button id="close" aria-label=""></button>
An empty aria-label results in no accessible name.
Incorrect: aria-labelledby pointing to a missing or empty element
<button id="save" aria-labelledby="save-label"></button>
<div id="save-label"></div>
The referenced element exists but contains no text, so the button has no accessible name.
Correct: button with visible text
<button>Submit order</button>
Correct: icon button with aria-label
<button aria-label="Close dialog">
<svg aria-hidden="true" focusable="false">
<use href="#icon-close"></use>
</svg>
</button>
The aria-label provides the accessible name, while aria-hidden="true" on the SVG prevents duplicate announcements.
Correct: button labeled by another element
<h2 id="section-title">Shopping cart</h2>
<button aria-labelledby="section-title">
<svg aria-hidden="true" focusable="false">
<use href="#icon-arrow"></use>
</svg>
</button>
The button's accessible name is drawn from the referenced heading text.
Correct: button with aria-label and visible text
<button aria-label="Search products">Search</button>
When both aria-label and inner text are present, aria-label takes precedence as the accessible name. Use this when you need a more descriptive name than what the visible text alone conveys.
Correct: button with title (last resort)
<button title="Print this page">
<svg aria-hidden="true" focusable="false">
<use href="#icon-print"></use>
</svg>
</button>
The title attribute provides an accessible name, but visible text or aria-label are preferred because title tooltips may not be available to touch-screen or keyboard-only users.
Websites typically repeat navigation links, branding, and other interface elements across every page. While sighted mouse users can visually scan past these blocks and click wherever they want, keyboard-only users and screen reader users must navigate through every interactive element sequentially. Without a bypass mechanism, a keyboard user might need to press Tab dozens of times just to reach the primary content on each new page they visit. For users with severe motor impairments, this can take several minutes per page and cause fatigue or physical pain. Even users with less severe limitations will experience frustrating delays compared to mouse users, who can reach any link in a second or two.
Screen reader users also benefit significantly from bypass mechanisms. Landmarks like <main>, <nav>, and <header> allow screen readers to present a structural outline of the page, enabling users to jump directly to the section they need. Headings serve a similar purpose — screen reader users can navigate by heading level to quickly locate the main content area.
This rule maps to WCAG 2.4.1 Bypass Blocks (Level A), which requires that a mechanism is available to bypass blocks of content repeated on multiple pages. It is also required by Section 508 (specifically §1194.22(o)), the Trusted Tester guidelines, and EN 301 549. Because it is a Level A requirement, it represents the minimum baseline for accessibility compliance.
How the Rule Works
The axe bypass rule checks that a page includes at least one of the following:
- A landmark region (such as
<main>, <nav>, <header>, or <footer>) - A heading (an
<h1> through <h6> element) - An internal skip link (an anchor link that points to a location further down the page)
If none of these are present, the rule flags the page as a failure.
How to Fix It
The best approach is to use HTML5 landmark elements to structure your page. At a minimum, include a <main> element that wraps the primary content of the page. You should also use <header>, <nav>, and <footer> to identify other common sections. A page should have only one <main> landmark.
Additionally, consider adding a skip navigation link as the very first focusable element on the page. This provides an immediate shortcut for keyboard users who don't use screen readers and may not be able to navigate by landmarks.
Prefer native HTML5 elements over their ARIA equivalents. For example, use <main> rather than <div role="main">. Native elements are better supported and require less code.
Examples
Incorrect: No Landmarks, Headings, or Skip Links
This page has no structural landmarks, no headings, and no skip link. Keyboard users must tab through every element to reach the content.
<div class="header">
<div class="logo">My Site</div>
<div class="nav">
<a href="/home">Home</a>
<a href="/about">About</a>
<a href="/contact">Contact</a>
</div>
</div>
<div class="content">
<p>This is the main content of the page.</p>
</div>
<div class="footer">
<p>Footer information</p>
</div>
Correct: Using HTML5 Landmark Elements
Replacing generic <div> wrappers with semantic HTML5 elements gives the page proper structure that assistive technologies can use for navigation.
<header>
<div class="logo">My Site</div>
<nav>
<a href="/home">Home</a>
<a href="/about">About</a>
<a href="/contact">Contact</a>
</nav>
</header>
<main>
<h1>Welcome</h1>
<p>This is the main content of the page.</p>
<section>
<h2>Latest News</h2>
<p>Section content here.</p>
</section>
</main>
<footer>
<p>Footer information</p>
</footer>
Correct: Adding a Skip Navigation Link
A skip link gives keyboard users an immediate way to bypass repeated content. It is typically visually hidden until it receives focus.
<body>
<a class="skip-link" href="#main-content">Skip to main content</a>
<header>
<nav>
<a href="/home">Home</a>
<a href="/about">About</a>
<a href="/contact">Contact</a>
</nav>
</header>
<main id="main-content">
<h1>Page Title</h1>
<p>This is the main content of the page.</p>
</main>
<footer>
<p>Footer information</p>
</footer>
</body>
.skip-link {
position: absolute;
left: -9999px;
top: auto;
width: 1px;
height: 1px;
overflow: hidden;
}
.skip-link:focus {
position: static;
width: auto;
height: auto;
overflow: visible;
}
When the skip link receives keyboard focus, it becomes visible, and pressing Enter moves focus directly to the <main> element. Combined with proper landmark elements, this gives all users fast, reliable access to the page's primary content.
Color contrast is one of the most common accessibility barriers on the web. When text doesn't stand out enough from its background, it becomes difficult or impossible to read for many users. People with low vision experience reduced contrast sensitivity, meaning everything appears roughly the same brightness, making it hard to distinguish outlines, edges, and details. Approximately 1 in 12 people cannot see the full spectrum of colors — about 8% of men and 0.4% of women in the United States have some form of color vision deficiency. Nearly three times as many people have low vision compared to total blindness. Without sufficient contrast, these users simply cannot read your content.
This rule maps to WCAG 2.1 Success Criterion 1.4.3: Contrast (Minimum), which is a Level AA requirement. It is also referenced in WCAG 2.0, WCAG 2.2, the Trusted Tester methodology, EN 301 549, and RGAA. The user impact is considered serious because insufficient contrast directly prevents users from perceiving text content.
How Contrast Ratios Work
Contrast ratio is calculated by comparing the relative luminance of two colors on a scale from 1:1 (no contrast, e.g., white on white) to 21:1 (maximum contrast, black on white). WCAG defines two thresholds:
- Normal text (below 18pt or below 14pt bold): minimum 4.5:1 contrast ratio
- Large text (at least 18pt / 24px, or at least 14pt bold / 19px): minimum 3:1 contrast ratio
"Large text" is defined this way because larger characters have wider strokes that are easier to read at lower contrast levels.
What This Rule Checks
The color-contrast rule in axe-core examines each text element on the page and compares the computed foreground text color against the computed background color. It accounts for background color transparency and opacity. Elements that are found to have a 1:1 contrast ratio are flagged as "incomplete" and require manual review.
This rule does not flag:
- Text elements with a
background-image (these require manual testing) - Text that is visually hidden by other overlapping elements
- Images of text
- Text inside disabled controls (including child elements of disabled buttons)
Some foreground scenarios are harder for automated tools to evaluate, including CSS gradients, pseudo-element backgrounds, backgrounds created with CSS borders, and elements repositioned off-screen with CSS.
How to Fix It
- Identify the failing elements by running axe. Each violation will report the current contrast ratio and the colors involved.
- Adjust the foreground color, background color, or both until the required ratio is met (4.5:1 for normal text, 3:1 for large text).
- Use a contrast checker tool like the axe DevTools browser extension, the WebAIM Contrast Checker, or the built-in color contrast analyzer in browser developer tools to test color combinations before deploying.
- Test with real content — sometimes dynamic content or themed components produce contrast issues that static checks miss.
Examples
Insufficient contrast (fails)
This light gray text on a white background has a contrast ratio of approximately 2.6:1, which fails the 4.5:1 requirement.
<p style="color: #aaaaaa; background-color: #ffffff;">
This text is hard to read.
</p>
Sufficient contrast (passes)
Darkening the text color to #595959 against a white background achieves a contrast ratio of approximately 7:1, meeting the requirement.
<p style="color: #595959; background-color: #ffffff;">
This text is easy to read.
</p>
Large text with lower contrast requirement (passes)
Large text (18pt or larger) only needs a 3:1 contrast ratio. This example uses #767676 on white, which has a ratio of approximately 4.5:1 — well above the 3:1 threshold for large text.
<h1 style="font-size: 24pt; color: #767676; background-color: #ffffff;">
Large heading text
</h1>
Semi-transparent background (fails)
Transparency can reduce effective contrast. Here, the semi-transparent white background doesn't provide enough contrast depending on what's behind it.
<div style="background-color: #cccccc;">
<p style="color: #777777; background-color: rgba(255, 255, 255, 0.3);">
Text with a semi-transparent background.
</p>
</div>
Semi-transparent background fixed (passes)
Increasing the background opacity or adjusting colors restores sufficient contrast.
<div style="background-color: #cccccc;">
<p style="color: #333333; background-color: rgba(255, 255, 255, 0.85);">
Text with a more opaque background.
</p>
</div>
Using CSS classes (passes)
In practice, you'll likely use CSS classes rather than inline styles. Ensure your design system tokens and theme colors meet contrast requirements.
<style>
.card {
background-color: #1a1a2e;
}
.card-text {
color: #e0e0e0;
}
</style>
<div class="card">
<p class="card-text">
Light text on a dark background with good contrast.
</p>
</div>
When a web page uses CSS media queries like @media (orientation: portrait) or @media (orientation: landscape) to force content into a single orientation, it prevents the page from responding to the user's actual device position. This is checked by the axe rule css-orientation-lock.
Why this matters
Many users physically cannot rotate their devices. People with mobility impairments may have their phone or tablet mounted to a wheelchair, bed, or desk in a fixed orientation. Users with low vision may prefer landscape mode to enlarge text, while others may find portrait easier to read. Locking orientation removes their ability to choose what works best for them.
Beyond motor and vision disabilities, orientation locking also affects users with cognitive disabilities and dyslexia who may rely on a particular layout for readability. Sighted keyboard users who use external displays or stands may also be impacted.
This rule relates to WCAG 2.1 Success Criterion 1.3.4: Orientation (Level AA), which requires that content not restrict its view and operation to a single display orientation unless a specific orientation is essential. Essential use cases are rare — examples include a piano keyboard app, a bank check deposit interface, or a presentation slide display where the orientation is integral to the functionality.
How to fix it
- Remove orientation-locking CSS. Look for
@media queries that use the orientation feature combined with styles that effectively hide or completely rearrange content for only one orientation (e.g., setting display: none or width: 0 on the body or main content). - Use responsive design instead. Rather than checking orientation, use
min-width or max-width media queries to adapt your layout to available space. This naturally accommodates both orientations. - Test in both orientations. Rotate your device or use browser developer tools to simulate both portrait and landscape modes. Verify that all content remains visible and functional.
- Only lock orientation when essential. If your application genuinely requires a specific orientation for core functionality (not just aesthetic preference), document the rationale. This is the only valid exception.
Examples
Incorrect: Locking content to portrait only
This CSS hides the main content area when the device is in landscape orientation, effectively forcing users to use portrait mode:
<style>
@media (orientation: landscape) {
.content {
display: none;
}
.rotate-message {
display: block;
}
}
@media (orientation: portrait) {
.rotate-message {
display: none;
}
}
</style>
<div class="content">
<h1>Welcome to our site</h1>
<p>This content is only visible in portrait mode.</p>
</div>
<div class="rotate-message">
<p>Please rotate your device to portrait mode.</p>
</div>
Incorrect: Using transform to force portrait layout in landscape
<style>
@media (orientation: landscape) {
body {
transform: rotate(-90deg);
transform-origin: top left;
width: 100vh;
height: 100vw;
overflow: hidden;
position: absolute;
}
}
</style>
This forcibly rotates the entire page, fighting against the user's chosen orientation and creating a confusing, inaccessible experience.
Correct: Responsive layout that works in both orientations
<style>
.content {
padding: 1rem;
}
.grid {
display: grid;
grid-template-columns: 1fr;
gap: 1rem;
}
@media (min-width: 600px) {
.grid {
grid-template-columns: 1fr 1fr;
}
}
</style>
<div class="content">
<h1>Welcome to our site</h1>
<div class="grid">
<div>
<p>Column one content.</p>
</div>
<div>
<p>Column two content.</p>
</div>
</div>
</div>
This approach uses min-width instead of orientation, adapting the layout based on available space. The content remains fully accessible and readable whether the device is held in portrait or landscape.
Correct: Using orientation queries for minor style adjustments (not locking)
<style>
.hero-image {
width: 100%;
height: 200px;
object-fit: cover;
}
@media (orientation: landscape) {
.hero-image {
height: 300px;
}
}
</style>
<img class="hero-image" src="hero.jpg" alt="A scenic mountain landscape">
Using orientation media queries is acceptable when you're making minor visual adjustments without hiding or restricting access to content. The key is that all content and functionality remain available in both orientations.
Screen readers announce definition lists in a specific way, conveying the relationship between terms (<dt>) and their descriptions (<dd>). When a <dl> element contains invalid direct children — such as <p>, <span>, or <li> elements — or when <dt> and <dd> elements appear in the wrong order, assistive technology cannot reliably parse the list. This primarily affects blind and deafblind users who depend on screen readers to understand content structure.
For example, a screen reader might announce a definition list by saying "definition list with 3 items," then reading each term followed by its definition. If the markup is malformed, the screen reader may skip items, miscount them, or fail to associate terms with their definitions.
This rule maps to WCAG Success Criterion 1.3.1: Info and Relationships (Level A), which requires that information, structure, and relationships conveyed visually are also available programmatically. A properly structured <dl> ensures the semantic relationship between terms and definitions is preserved in the accessibility tree.
How to Fix It
Follow these rules when building definition lists:
- Direct children of
<dl> must be limited to: <dt>, <dd>, <div>, <script>, or <template> elements. No other elements (like <p>, <span>, <li>, or plain text nodes) should appear as direct children. - Ordering matters: One or more
<dt> elements must come before one or more <dd> elements. A <dd> should never precede a <dt> within a group. - Using
<div> as a wrapper: You may wrap a <dt>/<dd> group in a <div> for styling purposes, but each <div> must contain a complete group (at least one <dt> followed by at least one <dd>). - No stray content: Don't place bare text or non-allowed elements directly inside the
<dl>.
Examples
Incorrect: Invalid direct child element
The <p> element is not a valid direct child of <dl>.
<dl>
<p>Beverage Types</p>
<dt>Coffee</dt>
<dd>A black hot drink made from roasted beans</dd>
</dl>
Incorrect: Wrong order of <dt> and <dd>
The <dd> element must follow the <dt>, not precede it.
<dl>
<dd>A black hot drink made from roasted beans</dd>
<dt>Coffee</dt>
</dl>
Incorrect: <dd> without a preceding <dt>
Every <dd> must be associated with at least one <dt>.
<dl>
<dd>An orphan definition with no term</dd>
</dl>
Correct: Basic definition list
<dl>
<dt>Coffee</dt>
<dd>A black hot drink made from roasted beans</dd>
<dt>Milk</dt>
<dd>A white cold drink</dd>
</dl>
Correct: Multiple definitions for a single term
<dl>
<dt>Coffee</dt>
<dd>A black hot drink made from roasted beans</dd>
<dd>A stimulating beverage containing caffeine</dd>
</dl>
Correct: Using <div> to wrap groups
Wrapping <dt>/<dd> groups in <div> elements is valid and useful for styling.
<dl>
<div>
<dt>Coffee</dt>
<dd>A black hot drink made from roasted beans</dd>
</div>
<div>
<dt>Milk</dt>
<dd>A white cold drink</dd>
</div>
</dl>
Correct: Multiple terms sharing one definition
<dl>
<dt>Latte</dt>
<dt>Café au lait</dt>
<dd>A coffee drink made with espresso and steamed milk</dd>
</dl>
Description lists follow a specific structural hierarchy in HTML. The <dl> element defines the list, and within it, <dt> elements represent terms while <dd> elements provide their corresponding descriptions. When <dt> or <dd> elements exist outside of a <dl>, the browser has no context to establish the relationship between terms and definitions. This makes the content semantically meaningless to assistive technologies.
Screen reader users are most affected by this issue. Screen readers announce description lists with specific cues — for example, telling users they've entered a list, how many items it contains, and the relationship between terms and descriptions. When <dt> and <dd> elements lack a <dl> parent, these announcements don't occur, and users who are blind or deafblind lose important structural context. Keyboard-only users and users with mobility impairments who rely on assistive technologies are also affected, as their tools may not properly navigate orphaned list items.
This rule relates to WCAG 2.0, 2.1, and 2.2 Success Criterion 1.3.1: Info and Relationships (Level A), which requires that information, structure, and relationships conveyed through presentation can be programmatically determined. A description list's structure conveys a meaningful relationship between terms and definitions, so the proper HTML hierarchy must be in place for that relationship to be communicated to all users.
How to fix it
- Wrap orphaned
<dt> and <dd> elements inside a <dl> parent element. - Ensure proper ordering —
<dt> elements should come before their associated <dd> elements. - Only place
<dt> and <dd> elements (or <div> elements that group <dt>/<dd> pairs) as direct children of <dl>. - Each
<dt> should have at least one corresponding <dd>, and vice versa, to form a complete term-description pair.
Examples
Incorrect: <dt> and <dd> without a <dl> parent
<dt>Coffee</dt>
<dd>A hot, caffeinated beverage</dd>
<dt>Milk</dt>
<dd>A cold, dairy-based drink</dd>
This is invalid because the <dt> and <dd> elements are not wrapped in a <dl>. Screen readers will not recognize these as a description list, and users will miss the term-definition relationships.
Correct: <dt> and <dd> wrapped in a <dl>
<dl>
<dt>Coffee</dt>
<dd>A hot, caffeinated beverage</dd>
<dt>Milk</dt>
<dd>A cold, dairy-based drink</dd>
</dl>
Correct: using <div> to group term-description pairs inside <dl>
HTML allows <div> elements as direct children of <dl> to group each <dt>/<dd> pair, which can be useful for styling:
<dl>
<div>
<dt>Coffee</dt>
<dd>A hot, caffeinated beverage</dd>
</div>
<div>
<dt>Milk</dt>
<dd>A cold, dairy-based drink</dd>
</div>
</dl>
Incorrect: <dd> nested inside an unrelated element
<div>
<dd>This description has no list context</dd>
</div>
A <dd> inside a <div> (or any non-<dl> parent) is invalid. Replace the <div> with a <dl> and add a corresponding <dt>:
<dl>
<dt>Term</dt>
<dd>This description now has proper list context</dd>
</dl>
The <title> element is the very first piece of information screen reader users hear when a page loads. It's also what appears in browser tabs, bookmarks, and search engine results. When a page has no title — or has an empty or generic one like "Untitled" — screen reader users are forced to read through the page content to figure out its purpose. For users who navigate between multiple open tabs or use their browser history to find a previous page, missing or vague titles create serious barriers.
This rule relates to WCAG 2.4.2 Page Titled (Level A), which requires that web pages have titles describing their topic or purpose. Because this is a Level A criterion, it represents a minimum baseline for accessibility. The rule also aligns with Trusted Tester guideline 12.A and EN 301 549.
The users most affected by missing or poor page titles include:
- Screen reader users (blind and deafblind users), who rely on the title as the first orientation cue when a page loads
- Users with cognitive disabilities, who benefit from clear, descriptive titles to understand where they are
- Keyboard-only users and anyone navigating between multiple tabs, who use titles to distinguish pages
How to fix it
- Add a
<title> element inside the <head> of every HTML document. - Write meaningful text inside the
<title> — it must not be empty or contain only whitespace. - Make each title unique across your site so users can distinguish between pages.
- Put the most unique information first. If you include a site or brand name, place it at the end (e.g., "Contact Us – Acme Corp" rather than "Acme Corp – Contact Us"). This way, screen reader users hear the distinguishing content immediately instead of listening to the same brand name on every page.
- Align the title with the page's
<h1> heading. They don't need to be identical, but they should be closely related since both describe the page's purpose. - Avoid placeholder text like "Untitled," "Page 1," or "New Document."
Beyond accessibility, descriptive titles improve SEO since search engines use them to filter, rank, and display results.
Examples
Incorrect: missing <title> element
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
</head>
<body>
<h1>Our Products</h1>
</body>
</html>
This page has no <title> element at all. Screen reader users will hear no identifying information when the page loads.
Incorrect: empty <title> element
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<h1>Our Products</h1>
</body>
</html>
A <title> element is present but contains no text, which is equivalent to having no title.
Incorrect: generic or placeholder title
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Untitled Document</title>
</head>
<body>
<h1>Our Products</h1>
</body>
</html>
While technically not empty, a placeholder title provides no useful information about the page's content.
Correct: descriptive and unique title
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Our Products – Acme Corp</title>
</head>
<body>
<h1>Our Products</h1>
</body>
</html>
The title clearly describes the page content, places the unique information first, and includes the site name at the end for context. It also closely matches the <h1> heading on the page.
Why This Is an Accessibility Problem
In HTML, the id attribute is designed to be a unique identifier for a single element in the document. When two or more elements share the same id, the browser has no reliable way to determine which element is being referenced. This becomes a critical accessibility barrier when that id is used to create relationships between elements — such as linking a <label> to a form input, or connecting a description to a widget via aria-describedby.
Assistive technologies like screen readers rely on these id-based relationships to communicate information to users. When duplicates exist, the screen reader will typically resolve the reference to the first element in the DOM with that id, which may not be the intended target. This means:
- A blind or deafblind user may hear the wrong label for a form field, or no label at all.
- An ARIA relationship like
aria-labelledby or aria-describedby may point to the wrong content, giving users incorrect or missing context. - Interactive components that depend on
aria-owns, aria-controls, or aria-activedescendant may break entirely.
This rule relates to WCAG Success Criterion 4.1.2: Name, Role, Value (Level A), which requires that all user interface components have accessible names and roles that can be programmatically determined. Duplicate id values used in ARIA or label associations directly undermine this requirement by creating ambiguous or broken programmatic relationships.
How to Fix It
- Identify all duplicate
id values that are referenced by ARIA attributes (aria-labelledby, aria-describedby, aria-controls, aria-owns, aria-activedescendant, etc.) or by a <label> element's for attribute. - Rename the duplicate
id values so that each one is unique within the document. - Update any references to those
id values in ARIA attributes or for attributes to match the new unique values. - Verify that each relationship still works correctly by testing with a screen reader or the axe accessibility checker.
Examples
Incorrect: Duplicate id on elements referenced by for
In this example, two inputs share the same id of "email". The second <label> intends to reference the second input, but both for attributes resolve to the first input.
<label for="email">Personal Email</label>
<input type="email" id="email">
<label for="email">Work Email</label>
<input type="email" id="email">
A screen reader user tabbing to the second input would hear no label or the wrong label, making it impossible to know what information to enter.
Correct: Unique id values for each input
<label for="personal-email">Personal Email</label>
<input type="email" id="personal-email">
<label for="work-email">Work Email</label>
<input type="email" id="work-email">
Incorrect: Duplicate id referenced by aria-labelledby
<span id="section-title">Shipping Address</span>
<div role="group" aria-labelledby="section-title">
<!-- shipping fields -->
</div>
<span id="section-title">Billing Address</span>
<div role="group" aria-labelledby="section-title">
<!-- billing fields -->
</div>
Both groups would be announced as "Shipping Address" because the browser resolves both aria-labelledby references to the first <span> with id="section-title".
Correct: Unique id values for each referenced element
<span id="shipping-title">Shipping Address</span>
<div role="group" aria-labelledby="shipping-title">
<!-- shipping fields -->
</div>
<span id="billing-title">Billing Address</span>
<div role="group" aria-labelledby="billing-title">
<!-- billing fields -->
</div>
Incorrect: Duplicate id used in aria-describedby
<p id="hint">Must be at least 8 characters.</p>
<label for="password">Password</label>
<input type="password" id="password" aria-describedby="hint">
<p id="hint">Re-enter your password to confirm.</p>
<label for="confirm-password">Confirm Password</label>
<input type="password" id="confirm-password" aria-describedby="hint">
Correct: Unique id values for each description
<p id="password-hint">Must be at least 8 characters.</p>
<label for="password">Password</label>
<input type="password" id="password" aria-describedby="password-hint">
<p id="confirm-hint">Re-enter your password to confirm.</p>
<label for="confirm-password">Confirm Password</label>
<input type="password" id="confirm-password" aria-describedby="confirm-hint">
When a form field has more than one <label> element pointing to it (either via the for attribute or by nesting), assistive technologies have no reliable way to determine which label is the correct one. This inconsistency means that users who are blind, have low vision, or are deafblind may hear the wrong label, an incomplete label, or a confusing combination of labels when interacting with a form. Users with mobility impairments also benefit from properly associated labels, since a single clear <label> expands the clickable area of the associated input.
This rule relates to WCAG 2.0, 2.1, and 2.2 Success Criterion 3.3.2: Labels or Instructions (Level A), which requires that labels or instructions are provided when content requires user input. Multiple conflicting labels undermine this requirement because the user cannot reliably receive a single, clear label for the field.
How to Fix
Ensure that each form field has only one <label> element associated with it. You can associate a label with a field in one of two ways — but use only one label per field:
- Explicit association — Use the
for attribute on the <label> matching the id of the input. - Implicit association — Wrap the input inside the
<label> element.
If you need to provide additional descriptive text beyond the label, use aria-describedby to point to supplementary instructions rather than adding a second <label>.
If you have a situation where one label must be visually hidden, hide the redundant label using CSS (display: none or visibility: hidden) so it is fully removed from the accessibility tree, and remove its for attribute. Using aria-hidden="true" alone on a <label> is not sufficient to prevent all screen readers from associating it with the field.
Examples
Incorrect: Two explicit labels for one input
Both <label> elements use for="username", causing unpredictable screen reader behavior.
<label for="username">Username</label>
<label for="username">Enter your username</label>
<input type="text" id="username" />
Incorrect: One explicit and one implicit label
The input is both wrapped in a <label> and referenced by another <label> via for.
<label for="email">Email</label>
<label>
Email address:
<input type="text" id="email" />
</label>
Incorrect: Nested labels
Labels should never be nested inside each other.
<label>
Enter your comments:
<label>
Comments:
<textarea id="comments"></textarea>
</label>
</label>
Correct: Single explicit label
One <label> with a for attribute matching the input's id.
<label for="username">Username</label>
<input type="text" id="username" />
Correct: Single implicit label
The input is wrapped inside a single <label>.
<label>
Email address:
<input type="text" id="email" />
</label>
Correct: Label with supplementary instructions using aria-describedby
When you need to provide extra guidance beyond the label, use aria-describedby instead of a second label.
<label for="password">Password</label>
<input type="password" id="password" aria-describedby="password-hint" />
<p id="password-hint">Must be at least 8 characters with one number.</p>
Correct: Using the title attribute as a label
When a visible label is not appropriate (rare cases), the title attribute can serve as an accessible name.
<textarea id="search" title="Search terms"></textarea>
Correct: Select inside a single label
<label>
Choose an option:
<select id="options">
<option selected>Option A</option>
<option>Option B</option>
</select>
</label>
When a <frame> or <iframe> has tabindex="-1", the browser removes it from the sequential keyboard navigation order. This means that any focusable elements inside the frame — such as links, buttons, form controls, or other interactive elements — become completely unreachable via the keyboard. If the frame also has scrollable content, keyboard users cannot scroll it either, since focus can never enter the frame to begin with.
This creates a serious barrier for people who rely on keyboards to navigate, including blind users who use screen readers and people with mobility disabilities who cannot use a mouse. Content trapped inside an inaccessible frame is effectively hidden from these users, even though it may be fully visible on screen.
Related WCAG Success Criteria
This rule maps to WCAG 2.1 Success Criterion 2.1.1: Keyboard (Level A), which requires that all functionality be operable through a keyboard interface without requiring specific timings for individual keystrokes. When focusable content is locked inside a frame with tabindex="-1", this criterion is violated because keyboard users cannot access or interact with that content.
This is a Level A requirement — the most fundamental level of accessibility — meaning it must be met for a page to be considered minimally accessible.
How to Fix It
- Remove
tabindex="-1" from any <frame> or <iframe> that contains focusable content. Without an explicit tabindex, the browser will handle focus naturally and allow keyboard users to tab into the frame. - Use
tabindex="0" if you need to explicitly include the frame in the tab order. - Only use
tabindex="-1" on frames that genuinely contain no focusable or interactive content. Even then, be cautious — if the frame's content changes later to include interactive elements, the negative tabindex will silently create an accessibility barrier.
As a general best practice, avoid using tabindex="-1" on frames entirely. It's easy for frame content to change over time, and a negative tabindex can turn into an accidental accessibility issue after a routine content update.
Examples
Incorrect: Frame with focusable content and tabindex="-1"
The button inside this iframe is unreachable by keyboard because tabindex="-1" prevents focus from entering the frame.
<iframe
srcdoc="<button>Click me</button>"
tabindex="-1"
title="Interactive widget">
</iframe>
Correct: Frame with focusable content and no negative tabindex
Removing tabindex="-1" allows keyboard users to tab into the frame and reach the button.
<iframe
srcdoc="<button>Click me</button>"
title="Interactive widget">
</iframe>
Correct: Frame with focusable content and tabindex="0"
Using tabindex="0" explicitly places the frame in the natural tab order.
<iframe
srcdoc="<button>Click me</button>"
tabindex="0"
title="Interactive widget">
</iframe>
Correct: Frame with no focusable content and tabindex="-1"
When a frame contains only static, non-interactive content (no links, buttons, or form controls), using tabindex="-1" is acceptable because there is nothing inside that requires keyboard access.
<iframe
srcdoc="<p>Hello world</p>"
tabindex="-1"
title="Static content display">
</iframe>
Screen reader users rely on frame titles to understand what each embedded region of a page contains. Many screen readers offer a feature that lists all frames on a page by their titles, allowing users to jump directly to the one they need. When frames lack titles or share identical titles, this feature becomes useless — users are left guessing which frame is which, or the screen reader falls back to unhelpful information like "frame," "javascript," a filename, or a URL.
This issue primarily affects users who are blind, deafblind, or who navigate with assistive technologies. It relates to WCAG 2.0, 2.1, and 2.2 Success Criterion 4.1.2: Name, Role, Value (Level A), which requires that all user interface components have an accessible name that can be programmatically determined. When frames share a title, their accessible names fail to uniquely identify them, violating this criterion. The rule is also covered by Trusted Tester guideline 12.D, which requires that the combination of accessible name and description for each <iframe> describes its content, as well as EN 301 549 section 9.4.1.2.
How to Fix It
- Add a
title attribute to every <frame> and <iframe> element. - Make each title unique across the page. No two frames should share the same title.
- Make each title descriptive. The title should clearly summarize the content or purpose of the frame. Avoid generic labels like "frame" or "untitled."
- Match the frame's inner document
<title> to the title attribute on the frame element when possible. Some screen readers replace the frame's title attribute with the inner document's <title> element, so keeping them consistent ensures a reliable experience.
Tips for Writing Good Frame Titles
- Keep titles brief but informative — describe what the frame contains, not just that it exists.
- Put the most distinctive information first. If you include a brand name, place it at the end so users don't have to hear it repeatedly while scanning a list of frames.
- Replace placeholder titles like "untitled" or "page" with meaningful descriptions.
- If the framed content has a visible heading, consider aligning the frame title with that heading for consistency.
Examples
Incorrect: Frames with Duplicate Titles
In this example, two iframes share the same title, making it impossible for screen reader users to tell them apart.
<iframe src="/news.html" title="Company Updates"></iframe>
<iframe src="/events.html" title="Company Updates"></iframe>
Incorrect: Frame with an Empty Title
An empty title provides no useful information to assistive technology users.
<iframe src="/contact.html" title=""></iframe>
Incorrect: Frames with No Title
Without any title attribute, screen readers fall back to announcing unhelpful information like the URL or "frame."
<iframe src="/navigation.html"></iframe>
<iframe src="/main-content.html"></iframe>
Correct: Frames with Unique, Descriptive Titles
Each frame has a distinct title that clearly describes its content.
<iframe src="/news.html" title="Latest Company News"></iframe>
<iframe src="/events.html" title="Upcoming Events Calendar"></iframe>
Correct: Frame Title Matching the Inner Document Title
For the best experience, align the title attribute with the <title> element in the framed document.
<!-- Parent page -->
<iframe src="/contact.html" title="Contact Form"></iframe>
<!-- contact.html -->
<!DOCTYPE html>
<html lang="en">
<head>
<title>Contact Form</title>
</head>
<body>
<h1>Contact Us</h1>
<form>
<label for="email">Email</label>
<input type="email" id="email" name="email">
<button type="submit">Send</button>
</form>
</body>
</html>
Correct: Hiding Decorative or Non-Content Frames
If a frame is purely decorative or contains no meaningful content for users (such as a tracking pixel), hide it from assistive technology entirely instead of giving it a misleading title.
<iframe src="/tracking-pixel.html" title="" aria-hidden="true" tabindex="-1"></iframe>
Note that this approach should only be used when the frame genuinely contains no content that any user would need to access.
Screen reader users can pull up a list of all frames on a page and navigate between them using their titles. When frames lack accessible names, users hear generic labels like "frame," "JavaScript," or a raw URL — none of which convey the purpose or content of the frame. This forces users to enter each frame just to figure out what it contains, which is time-consuming and frustrating.
This issue primarily affects users who are blind or deafblind and rely on assistive technology, but it also impacts users with mobility disabilities who navigate by frame lists or landmarks.
Relevant WCAG Success Criteria
This rule relates to WCAG 2.2 Success Criterion 4.1.2: Name, Role, Value (Level A), which requires that all user interface components have a name that can be programmatically determined. Frames are interactive containers that users navigate into and out of, so they must have an accessible name.
It is also explicitly required by Section 508 (§1194.22(i)), which states that frames shall be titled with text that facilitates frame identification and navigation.
How to Fix It
Give every <iframe> and <frame> element a clear, descriptive accessible name using one of these methods:
title attribute — The most common approach. Add a title that briefly describes the frame's content.aria-label attribute — Provides an accessible name directly on the element.aria-labelledby attribute — References another element's text as the accessible name.
Tips for Writing Good Frame Titles
- Be brief and descriptive. A title like "Product search results" is far more useful than "frame1" or "content."
- Make each title unique. If you have multiple frames, each one should have a distinct title so users can tell them apart.
- Match the frame's internal document title. Some screen readers replace the frame's
title attribute with the <title> element inside the framed document. For consistency, keep them the same or very similar. - Avoid placeholder text. Titles like "untitled" or "iframe" provide no useful information.
- Put unique information first. If you include a brand name, place it after the descriptive content so users hear the most useful information immediately.
Examples
Incorrect: <iframe> Without an Accessible Name
The frame has no title, aria-label, or aria-labelledby, so screen readers cannot describe it.
<iframe src="https://example.com/video-player"></iframe>
Incorrect: Empty title Attribute
An empty title is the same as having no title at all.
<iframe src="https://example.com/video-player" title=""></iframe>
Correct: Using the title Attribute
<iframe src="https://example.com/video-player" title="Product demo video player"></iframe>
Correct: Using aria-label
<iframe src="https://example.com/map" aria-label="Store location map"></iframe>
Correct: Using aria-labelledby
<h2 id="chat-heading">Live Chat Support</h2>
<iframe src="https://example.com/chat" aria-labelledby="chat-heading"></iframe>
Correct: Multiple Frames With Unique Titles
When a page contains several frames, each one should have a distinct, descriptive title.
<iframe src="/navigation" title="Site navigation menu"></iframe>
<iframe src="/content" title="Main article content"></iframe>
<iframe src="/ads" title="Sponsored advertisements"></iframe>
Correct: Matching the Frame Title to the Document Title
For the best experience, align the title attribute on the <iframe> with the <title> element inside the framed document.
<!-- Parent page -->
<iframe src="contact-form.html" title="Contact us form"></iframe>
<!-- contact-form.html -->
<!DOCTYPE html>
<html lang="en">
<head>
<title>Contact us form</title>
</head>
<body>
<h1>Contact Us</h1>
<form>
<label for="email">Email</label>
<input type="email" id="email">
<button type="submit">Send</button>
</form>
</body>
</html>
Screen readers rely on distinct sound libraries for each language, with pronunciation rules, intonation patterns, and phonetics tailored to that specific language. When a user navigates to a page, the screen reader checks the lang attribute on the <html> element to determine which sound library to load. If no lang attribute is present, the screen reader falls back to whatever default language the user configured during setup. For someone who speaks multiple languages and browses websites in different languages, this creates a serious problem — the screen reader will attempt to read foreign-language content using the wrong pronunciation rules, producing garbled or incomprehensible speech.
This issue primarily affects blind and deafblind users who rely on screen readers, but it also impacts users with cognitive disabilities who may use text-to-speech tools. When text is read aloud with the wrong language rules, even simple words become unrecognizable, effectively making the content inaccessible.
Related WCAG Success Criteria
This rule maps to WCAG 2.0, 2.1, and 2.2 Success Criterion 3.1.1: Language of Page at Level A — the most fundamental level of conformance. This criterion requires that the default human language of each web page can be programmatically determined. It is also referenced by the Trusted Tester guidelines (11.A), EN 301 549, and RGAA.
How to Fix It
Add a lang attribute with a valid language code to the opening <html> element. The value should represent the primary language of the page content.
You can use a simple two-letter language code (like en for English, fr for French, or de for German), or you can be more specific with a regional dialect code like en-US for American English or fr-CA for Canadian French. A full list of valid language subtags is available in the IANA Language Subtag Registry.
If sections of your page contain content in a different language than the primary one, use the lang attribute on those specific elements so screen readers can switch sound libraries mid-page.
For languages written right to left (such as Arabic or Hebrew), also include the dir attribute with a value of rtl to indicate the text direction.
Examples
Incorrect: Missing lang attribute
This will trigger the rule because the <html> element has no lang attribute:
<html>
<head>
<title>My Website</title>
</head>
<body>
<h1>Welcome</h1>
</body>
</html>
Correct: lang attribute with a valid language code
<html lang="en">
<head>
<title>My Website</title>
</head>
<body>
<h1>Welcome</h1>
</body>
</html>
Correct: Using a regional dialect code
<html lang="en-US">
<head>
<title>My Website</title>
</head>
<body>
<h1>Welcome</h1>
</body>
</html>
Correct: Handling inline language changes
When a portion of the page is in a different language, use the lang attribute on the containing element:
<html lang="en">
<head>
<title>My Website</title>
</head>
<body>
<p>The French word for hello is <span lang="fr">bonjour</span>.</p>
</body>
</html>
Correct: Right-to-left language with dir attribute
<html lang="ar" dir="rtl">
<head>
<title>موقعي</title>
</head>
<body>
<h1>مرحبا</h1>
</body>
</html>
Screen readers rely on language-specific sound libraries to pronounce text accurately. Each language has its own pronunciation rules, intonation patterns, and phonetic characteristics, so screen readers load the appropriate library based on the declared language of the document. When the <html> element has no lang attribute or contains an invalid value — such as a misspelling or a fabricated code — the screen reader cannot determine which library to use. It defaults to whatever language the user configured during setup, which means content written in French might be read aloud using English pronunciation rules. The result is speech that sounds like a confusing, unintelligible accent.
This issue primarily affects blind users and deafblind users who rely on screen readers, but it also impacts users with cognitive disabilities who may use text-to-speech tools to aid comprehension. When pronunciation is wrong, understanding drops dramatically.
Related WCAG Success Criteria
This rule maps to WCAG Success Criterion 3.1.1: Language of Page (Level A), which requires that the default human language of each web page can be programmatically determined. This is a Level A requirement — the most fundamental level of accessibility — meaning it must be satisfied for basic compliance under WCAG 2.0, 2.1, and 2.2. It is also required by the Trusted Tester methodology, EN 301 549, and RGAA.
How to Fix It
- Add a
lang attribute to the opening <html> element. - Set its value to a valid BCP 47 language tag that represents the primary language of the page.
- Double-check the spelling of the language code. Common valid codes include
"en" (English), "fr" (French), "es" (Spanish), "de" (German), "ja" (Japanese), and "ar" (Arabic). - You can optionally include a regional subtag, such as
"en-US" for American English or "fr-CA" for Canadian French. - For XHTML documents served as XML, use
xml:lang instead of or in addition to lang.
If the language changes within the document for specific passages, use the lang attribute on the appropriate element to indicate the switch. For right-to-left languages, also include the dir="rtl" attribute.
Examples
Incorrect: Missing lang attribute
<html>
<head>
<title>My Page</title>
</head>
<body>
<p>Welcome to my website.</p>
</body>
</html>
Without a lang attribute, screen readers cannot determine the page language and will default to the user's configured language, which may not match the content.
Incorrect: Invalid lang value
<html lang="english">
<head>
<title>My Page</title>
</head>
<body>
<p>Welcome to my website.</p>
</body>
</html>
The value "english" is not a valid BCP 47 language tag. The correct code for English is "en".
Correct: Valid lang attribute
<html lang="en">
<head>
<title>My Page</title>
</head>
<body>
<p>Welcome to my website.</p>
</body>
</html>
Correct: Regional subtag
<html lang="fr-CA">
<head>
<title>Ma page</title>
</head>
<body>
<p>Bienvenue sur mon site web.</p>
</body>
</html>
Correct: Language change within the page
<html lang="en">
<head>
<title>Multilingual Page</title>
</head>
<body>
<p>This paragraph is in English.</p>
<p lang="es">Este párrafo está en español.</p>
</body>
</html>
Correct: Right-to-left language
<html lang="ar" dir="rtl">
<head>
<title>صفحتي</title>
</head>
<body>
<p>مرحبا بكم في موقعي.</p>
</body>
</html>
The dir="rtl" attribute ensures the text direction is correctly rendered for right-to-left languages like Arabic and Hebrew.
The lang attribute tells browsers and assistive technologies what language the content is written in. The xml:lang attribute serves the same purpose but comes from the XML/XHTML specification. When both attributes are present on the same element—most commonly the <html> element—they must agree on the base language. The "base language" is the primary language subtag (e.g., en in en-US or fr in fr-CA). If one attribute says en and the other says fr, assistive technologies receive conflicting information and cannot reliably determine how to process the content.
Who is affected
This issue primarily impacts screen reader users, including people who are blind, deafblind, or have cognitive disabilities. Screen readers maintain separate pronunciation libraries for each language. When they encounter a language declaration, they switch to the appropriate library so words are spoken with correct pronunciation and cadence. A mismatch between lang and xml:lang can cause the screen reader to select the wrong library or behave unpredictably, making the content difficult or impossible to understand.
Users who speak multiple languages and browse sites in different languages are especially vulnerable, as they rely on accurate language declarations to switch between language contexts.
Related WCAG success criteria
This rule relates to WCAG Success Criterion 3.1.1: Language of Page (Level A), which requires that the default human language of each web page can be programmatically determined. This criterion applies across WCAG 2.0, 2.1, and 2.2, as well as EN 301 549 and RGAA. When lang and xml:lang conflict, the programmatically determined language becomes ambiguous, violating this requirement.
How to fix it
- Check the
<html> element (and any other elements) for the presence of both lang and xml:lang attributes. - Ensure both attributes use the same base language. For example, if
lang="en", then xml:lang must also start with en (e.g., en, en-US, or en-GB). - If you don't need
xml:lang, the simplest fix is to remove it entirely. The lang attribute alone is sufficient for HTML5 documents. - If you're serving XHTML, both attributes may be required. In that case, keep them in sync.
You can find valid language codes on the ISO 639 language codes reference page. Common codes include en for English, fr for French, es for Spanish, de for German, and ar for Arabic.
Examples
Incorrect: mismatched base languages
The lang attribute specifies English, but xml:lang specifies French. This creates a conflict that confuses assistive technologies.
<html lang="en" xml:lang="fr">
<head>
<title>My Page</title>
</head>
<body>
<p>Hello, world!</p>
</body>
</html>
Correct: matching base languages
Both attributes specify English. The dialect subtag may differ, but the base language (en) is the same.
<html lang="en-US" xml:lang="en-GB">
<head>
<title>My Page</title>
</head>
<body>
<p>Hello, world!</p>
</body>
</html>
Correct: identical values
The simplest and most reliable approach—use the exact same value for both attributes.
<html lang="en" xml:lang="en">
<head>
<title>My Page</title>
</head>
<body>
<p>Hello, world!</p>
</body>
</html>
Correct: only lang attribute (HTML5)
In HTML5 documents, the xml:lang attribute is not required. Using lang alone avoids any possibility of a mismatch.
<html lang="en">
<head>
<title>My Page</title>
</head>
<body>
<p>Hello, world!</p>
</body>
</html>
Correct: specifying language on inline elements
When content in a different language appears within the page, use the lang attribute on the appropriate element. If you also use xml:lang, make sure they match.
<p>Welcome to our site. <span lang="es" xml:lang="es">Bienvenidos a nuestro sitio.</span></p>
For right-to-left languages, also include the dir attribute:
<p lang="ar" xml:lang="ar" dir="rtl">مرحبا بكم في موقعنا</p>
Images are a fundamental part of web content, but they are inherently visual. Screen readers cannot interpret the pixels of an image — they rely entirely on a text alternative to describe the image's content and purpose to the user. Without alternative text, a screen reader may read out the image's file name (e.g., "IMG_20230415_093012.jpg"), which is meaningless and confusing. In the worst case, the image is silently skipped, and the user misses critical information.
This rule primarily affects people who are blind or deafblind, who depend on screen readers or braille displays to access content. Users with low vision who rely on text magnification or high-contrast modes can also benefit from well-written alternative text.
Why This Matters
This rule maps to WCAG 2.2 Success Criterion 1.1.1: Non-text Content (Level A), which requires that all non-text content presented to the user has a text alternative that serves an equivalent purpose. It is also required by Section 508 and EN 301 549. Because it is a Level A requirement, it represents the absolute minimum baseline for accessibility — failing it means your content is fundamentally inaccessible to many users.
How to Provide Alternative Text
There are three main techniques for giving an image accessible alternative text:
- The
alt attribute — the most common and preferred method for <img> elements. - The
aria-label attribute — provides an accessible name directly on the element. - The
aria-labelledby attribute — points to the id of another element that contains the descriptive text.
Writing Good Alt Text
When writing alternative text, consider these questions:
- Why is this image here? What role does it play in the content?
- What information does it convey? What would a sighted user take away from it?
- If you removed the image, what words would replace it to preserve the same meaning?
Keep alt text concise and descriptive. Avoid phrases like "image of" or "picture of" — screen readers already announce the element as an image. Don't use the file name as alt text. Focus on the image's purpose and meaning, not a pixel-by-pixel description.
Handling Decorative Images
Not every image carries meaning. Decorative images — such as visual separators, background flourishes, or images whose content is fully described in surrounding text — should be hidden from assistive technology. To do this, use an empty alt attribute: alt="".
Do not omit the alt attribute entirely. If alt is missing, screen readers will often fall back to reading the file name, which creates a worse experience than having no announcement at all. An empty alt="" explicitly tells the screen reader to skip the image.
You can also use role="presentation" or role="none" to mark an image as decorative, but an empty alt attribute is simpler and more widely supported.
Examples
Incorrect: Missing Alt Text
The alt attribute is completely absent. A screen reader may announce the file name instead.
<img src="team-photo.jpg">
Incorrect: Unhelpful Alt Text
The alt text contains the file name rather than a meaningful description.
<img src="chart-q3.png" alt="chart-q3.png">
Correct: Descriptive Alt Text Using the alt Attribute
<img src="team-photo.jpg" alt="The engineering team gathered around a whiteboard during a planning session">
Correct: Alt Text Using aria-label
<img src="revenue-chart.png" aria-label="Bar chart showing quarterly revenue increasing from $2M in Q1 to $3.5M in Q4">
Correct: Alt Text Using aria-labelledby
<p id="chart-desc">Bar chart showing quarterly revenue growth from Q1 to Q4 2024.</p>
<img src="revenue-chart.png" aria-labelledby="chart-desc">
Correct: Decorative Image with Empty Alt
This separator line serves no informational purpose and should be hidden from screen readers.
<img src="decorative-line.svg" alt="">
Correct: Decorative Image Using role="presentation"
<img src="decorative-swirl.png" role="presentation">
What This Rule Checks
This axe-core rule (image-alt) inspects every <img> element on the page and verifies that it has an accessible text alternative. Specifically, it checks that each <img> has at least one of the following:
- A non-empty
alt attribute - An
aria-label attribute - An
aria-labelledby attribute that references a valid element - An empty
alt="" (or role="presentation" / role="none") to indicate the image is decorative
If none of these conditions are met, the rule flags the image as a critical accessibility violation.
Every interactive control on a page needs an accessible name so that assistive technologies can announce it to users. For <input> elements with type="button", type="submit", or type="reset", the accessible name typically comes from the value attribute. While <input type="submit"> and <input type="reset"> have default browser-provided labels ("Submit" and "Reset"), <input type="button"> has no default — it renders as an empty, unlabeled button if no name is provided.
This issue critically affects blind and deafblind users who rely on screen readers. When a screen reader encounters an input button without discernible text, it may announce something like "button" with no indication of what the button does. This makes it impossible to navigate forms, submit data, or perform actions confidently. Sighted users can often infer a button's purpose from visual context, but screen reader users depend entirely on the programmatic accessible name.
Related WCAG Success Criteria
This rule maps to WCAG 2.2 Success Criterion 4.1.2: Name, Role, Value (Level A), which requires that all user interface components have a name that can be programmatically determined. It also relates to Section 508 requirements that every non-text element must have a text equivalent, and EN 301 549 Section 9.4.1.2.
How to Fix It
There are several ways to give an input button a discernible accessible name:
value attribute — The most straightforward approach. Set value to descriptive text that communicates the button's purpose.aria-label attribute — Provides an accessible name directly. Useful when you need the accessible name to differ from the visible text, or when value cannot be used.aria-labelledby attribute — References another element's id whose text content becomes the accessible name. The referenced element must exist and contain text.title attribute — Acts as a fallback accessible name. However, title is less reliable because it is not consistently exposed by all assistive technologies and only appears as a tooltip on hover, making it inaccessible to keyboard and touch users. Prefer value or aria-label instead.
For <input type="submit"> and <input type="reset">, browsers provide default labels, so they pass without an explicit value. However, if you set value="" (an empty string), you override the default and create an empty accessible name, which fails.
Examples
Incorrect: Input button with no accessible name
<form action="/search">
<input type="button" id="go" />
</form>
This button has no value, aria-label, aria-labelledby, or title. A screen reader will announce it as just "button" with no context.
Incorrect: Empty aria-label
<form action="/search">
<input type="button" aria-label="" />
</form>
An empty aria-label does not provide a discernible name.
Incorrect: aria-labelledby referencing a nonexistent or empty element
<form action="/search">
<input type="button" aria-labelledby="nonexistent" />
</form>
<form action="/search">
<input type="button" aria-labelledby="empty-label" />
<div id="empty-label"></div>
</form>
If the referenced element doesn't exist or has no text content, the button has no accessible name.
Incorrect: Submit or reset with an empty value
<form action="/search">
<input type="submit" value="" />
<input type="reset" value="" />
</form>
Setting value to an empty string overrides the browser's default label, leaving the button unnamed.
Correct: Using the value attribute
<form action="/search">
<input type="button" value="Search" />
</form>
Correct: Using aria-label