How to Fix Missing Alt Text (WCAG 2.2)

Applies to: SC 1.1.1 Non-text Content, Level A

Missing alt text was found on 53.1% of home pages in the WebAIM Million 2026 (detected with WebAIM's WAVE tool). 45% of images missing alt text were linked images, which leaves those links without a name (WebAIM).

Decide what each image needs (see the W3C alt decision tree)

• Informative image: describe the information it conveys, briefly.
• Linked or functional image: describe the destination or action (e.g. alt="Home" for a logo link), not how it looks.
• Decorative image: use an empty alt, alt="" (not a missing attribute), or apply it as a CSS background.
• Complex image (chart, diagram): give a short alt plus a longer description nearby.
• Text in images: the alt should contain the same text.

<img src="team.jpg" alt="Our five-person support team at the Perth office">
<a href="/"><img src="logo.svg" alt="Acme home"></a>
<img src="divider.png" alt="">

CMS-specific steps

• WordPress: select the Image block › Block settings › "Alternative text". You can also set it in Media Library › attachment details. (Image block docs) Note: alt text set in the Media Library may not update images already placed in posts. Check those posts. More detail, including featured images, galleries, logos and WooCommerce: How to add alt text in WordPress.
• Shopify: Products › select product › click the media item › Add alt text › Save. Bulk option: CSV upload. The media editor can suggest AI alt text; review it before accepting. (Shopify help, media editor) Theme section images have their own alt fields in the theme editor/Files. More detail, including variant photos, CSV bulk edits, theme images and images in descriptions: How to add alt text in Shopify.
• Webflow: select the image › Element settings › Image settings › Alt text › Custom description, or choose Decorative. Set defaults in the Assets panel. For CMS collections, use "Get alt text from" a collection field. (Webflow help, alt text article)
• Squarespace: edit the page › click the image block › pencil › Content tab › Image alt text. Image blocks and auto layouts have no alt text unless you add it. (Squarespace help)
• Wix: click the image › Settings icon › enter a description under "What's in the image?". Wix's Accessibility Wizard (Settings › Accessibility Wizard › Scan Site) can also flag images that need alt text. It doesn't scan every part of a site, and any AI-suggested alt text it offers needs the same review. (Wix help)

WordPress, Shopify, Webflow, Squarespace and Wix are trademarks of their respective owners. Glimscope is not affiliated with or endorsed by any of them.

What automated tools can and can't tell you: Automated checkers (including axe-core, which our monitor uses) can flag many instances of this issue, but they cannot judge everything. A human still has to check meaning and context. For scale: Deque reports that in its own sample of first-time audits, its automated tests found 57.38% of issues by volume (Deque report). That is Deque's figure for its sample, not a detection rate for any one tool, and it means a large share of issues still needs manual testing. A scanner can tell that an alt attribute is missing. It cannot tell whether existing alt text is accurate. alt="image123.jpg" or an unreviewed AI suggestion may "pass" a scan and still fail users. Automated tests find only some accessibility issues; manual testing is still required. Not legal advice.

Manual checklist

• Alt text describes purpose, not just appearance
• Linked images describe the destination
• Decorative images use alt=""
• No filenames or "image of…" padding