auditmysitev2.0.2

Missing alternative text on images

image-alt

WCAG success criterion
1.1.1 (level A)
Outcome class
Automatic. An automated check that can report a confirmed violation.
Area
Accessibility, Content & Alternatives
Default severity
high
axe-core rule
image-alt

Why we flag this

Screen reader users receive no image information.

Non-conformant image markup.

What the rule checks

Scope. Exposed AX image nodes that are not <img> (role="img" on other elements; <svg> findings are dropped for svg/name-missing), plus nodes named like icons.

Expectation. An element with role="img" (not <img>, not <svg>) without an accessible name has no text alternative: violation at the element. A name from aria-label / aria-labelledby passes; aria-hidden or otherwise ignored nodes are not exposed and not judged. A nameless graphic inside a link or button that has its own name adds nothing a user misses (the control carries the alternative) and passes. <img> belongs to images/alt-missing and is never reported here.

Source. WCAG 2.2 SC 1.1.1 Non-text Content (ARIA6, ARIA10, F65); WAI-ARIA 1.2 img role (name required); accname 1.2

Detection: tree; needs ax_tree.

Failing example

The check reports a violation here. Corpus case content_images_broken. The page may contain further findings for other rules.

content_images_broken.htmlHTML
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Exhibition with missing text alternatives</title>
    <style>
        @media (max-width: 600px) { .wide-only { display: none; } }
        @media (min-width: 601px) { .narrow-only { display: none; } }
        .icon { display: inline-block; width: 16px; height: 16px; background: #446; }
    </style>
    <style>
        nav a, .skip-link, form input { display: inline-block; min-width: 44px; min-height: 44px; }
    </style>
</head>
<body>
    <a class="skip-link" href="#main">Skip to main content</a>
    <header>
        <p>City Library</p>
        <nav aria-label="Main"><a href="/" aria-current="page">Home</a> <a href="/catalogue">Catalogue</a> <a href="/visit">Visit</a></nav>
    </header>
    <main id="main">
        <h1>Exhibition: maps of the old town</h1>
        <img id="poster" src="/poster.jpg" width="200" height="120">
        <img id="file-alt" src="/map-1850.png" alt="map-1850.png" width="200" height="120">
        <img id="short-alt" src="/seal.png" alt="ab" width="40" height="40">
        <img id="filler-alt" src="/gate.png" alt="Image" width="40" height="40">
        <img id="wide-banner" class="wide-only" src="/banner-wide.jpg" width="300" height="60">
        <img id="narrow-banner" class="narrow-only" src="/banner-narrow.jpg" width="100" height="60">
        <img id="town-map" src="/town.png" usemap="#town-areas" alt="Old town districts" width="200" height="120">
        <map name="town-areas">
            <area id="area-market" href="/districts/market" shape="rect" coords="0,0,100,60">
            <area id="area-harbour" href="/districts/harbour" shape="rect" coords="100,0,200,60" alt="Harbour">
        </map>
        <a href="/maps/click"><img id="server-map" src="/clickable.png" ismap alt="Clickable town map" width="200" height="120"></a>
        <form action="/search">
            <label for="q">Search the collection</label>
            <input id="q" name="q" type="search">
            <input id="search-go" type="image" src="/go.png">
        </form>
        <object id="catalogue-pdf" data="/catalogue.pdf" type="application/pdf" width="300" height="200"></object>
        <audio id="welcome-audio" autoplay src="/welcome.mp3"></audio>
        <div id="stamp" role="img" class="icon"></div>
        <gallery-card></gallery-card>
        <iframe id="frame-gallery" title="Gallery" style="width:400px;height:120px;border:0" srcdoc="<!DOCTYPE html><html lang=&quot;en&quot;><head><title>Gallery</title></head><body><img id=&quot;frame-photo&quot; src=&quot;/frame.jpg&quot; width=&quot;80&quot; height=&quot;60&quot;><div id=&quot;frame-stamp&quot; role=&quot;img&quot; style=&quot;width:16px;height:16px;background:#446&quot;></div></body></html>"></iframe>
        <div id="late-images"></div>
        <script>
            customElements.define('gallery-card', class extends HTMLElement {
                connectedCallback() {
                    this.attachShadow({ mode: 'open' }).innerHTML =
                        '<img id="shadow-photo" src="/reading-room.jpg" width="120" height="80">';
                }
            });
            document.getElementById('late-images').innerHTML =
                '<img id="late-photo" src="/late.jpg" width="120" height="80">';
        </script>
    </main>
    <footer><p>City Library, 1 Market Square</p></footer>
</body>
</html>

Passing example

The check passes here and reports nothing. Corpus case content_images_ok. The page may contain further findings for other rules.

content_images_ok.htmlHTML
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Exhibition: maps of the old town</title>
    <style>
        .icon { display: inline-block; width: 16px; height: 16px; background: #446; }
        .sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
    </style>
    <style>
        nav a, .skip-link, form input, a[href="/print"] { display: inline-block; min-width: 44px; min-height: 44px; }
    </style>
</head>
<body>
    <a class="skip-link" href="#main">Skip to main content</a>
    <header>
        <p>City Library</p>
        <nav aria-label="Main"><a href="/" aria-current="page">Home</a> <a href="/catalogue">Catalogue</a> <a href="/visit">Visit</a></nav>
    </header>
    <main id="main">
        <h1>Exhibition: maps of the old town</h1>
        <img id="poster" src="/poster.jpg" alt="Poster: maps of the old town, 3 May to 30 June" width="200" height="120">
        <img id="divider" src="/divider.png" alt="" width="200" height="4">
        <img id="labelled" src="/map-1850.png" aria-label="Town map of 1850" width="200" height="120">
        <p id="caption-1900">Town map of 1900</p>
        <img id="labelledby" src="/map-1900.png" aria-labelledby="caption-1900" width="200" height="120">
        <img id="titled" src="/seal.png" title="Town seal" width="40" height="40">
        <img id="three-chars" src="/sign.png" alt="Inn" width="40" height="40">
        <img id="presentational" src="/flourish.png" role="presentation" width="40" height="10">
        <img id="hidden-from-at" src="/flourish.png" aria-hidden="true" width="40" height="10">
        <img id="not-rendered" src="/print-only.png" style="display: none">
        <img id="hidden-attr" src="/later.png" hidden>
        <img id="town-map" src="/town.png" usemap="#town-areas" alt="Old town districts" width="200" height="120">
        <map name="town-areas">
            <area id="area-market" href="/districts/market" shape="rect" coords="0,0,100,60" alt="Market district">
            <area id="area-harbour" href="/districts/harbour" shape="rect" coords="100,0,200,60" aria-label="Harbour district">
            <area id="area-decor" shape="rect" coords="0,60,200,120">
        </map>
        <form action="/search">
            <label for="q">Search the collection</label>
            <input id="q" name="q" type="search">
            <input id="search-go" type="image" src="/go.png" alt="Search">
            <span id="reset-label" hidden>Clear search</span>
            <input id="search-clear" type="image" src="/clear.png" aria-labelledby="reset-label">
        </form>
        <object id="catalogue-pdf" data="/catalogue.pdf" type="application/pdf" width="300" height="200">
            <a href="/catalogue.pdf">Download the exhibition catalogue (PDF)</a>
        </object>
        <object id="floor-plan" data="/floor.svg" type="image/svg+xml" title="Floor plan of the exhibition" width="300" height="200"></object>
        <audio id="muted-loop" autoplay muted loop src="/ambience.mp3"></audio>
        <audio id="tour-audio" controls src="/tour.mp3"></audio>
        <span id="warning-icon" role="img" aria-label="Warning" class="icon"></span>
        <span id="decor-icon" role="img" class="icon" aria-hidden="true"></span>
        <a href="/print"><span id="print-icon" role="img" class="icon"></span>Print this page</a>
    </main>
    <footer><p>City Library, 1 Market Square</p></footer>
</body>
</html>

This page is generated from the rule catalogue and the rule contracts; see therule overview for how the outcome classes are derived.