Missing text alternative on embedded objects

objects/alt-missing

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: object-alt

Why we flag this

Screen reader users receive no information about the embedded object's content.

What the rule checks

Scope. Every rendered <object>.

Expectation. An <object> without fallback text, aria-label, aria-labelledby or title has no text alternative (H53): violation at the object. Fallback content with text (a download link) or a title passes.

Source. WCAG 2.2 SC 1.1.1 Non-text Content (H37, H24, H36, H53, ARIA6, ARIA10, F65, F30); HTML §4.8; accname 1.2; HTML §4.8.7 object (fallback content)

Detection: shared; needs dom, computed_style.

Failing example

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

object_no_alt.htmlHTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>Object missing alternative corpus case</title>
</head>
<body>
    <main>
        <h1>Embedded object without a text alternative</h1>
        <object data="/report.pdf" type="application/pdf" width="400" height="300"></object>
    </main>
</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.