UK legal requirement: Equality Act 2010 and WCAG 2.2
In the UK, the Equality Act 2010 requires organisations to make reasonable adjustments so that disabled people are not put at a disadvantage. For websites, this means accessible images , including proper alt text. Public-sector websites must meet WCAG 2.1 AA under the Public Sector Bodies Accessibility Regulations 2018. WCAG 2.2 Success Criterion 1.1.1 (Level A) requires all non-text content to have a text alternative. Missing alt text is the most common Level A violation found in GDS (Government Digital Service) accessibility audits.
Screen readers widely used in the UK include NVDA (free, popular for desktop), JAWS (widely used in professional and public-sector settings), and VoiceOver (built into Apple devices). Each announces images differently: NVDA reads the filename if no alt is present, which produces unhelpful output like "DSC00342.jpg". The GOV.UK style guide for alt text is specific: describe the informational content, not the aesthetics.
Alt text quality audit: what this tool checks
| Issue | Impact | Fix |
|---|---|---|
| Missing alt attribute | Screen reader reads filename or nothing | Add descriptive alt or alt="" for decorative |
| Empty alt on informative image | Image content invisible to screen reader | Add description of image purpose |
| Alt starts with "image of" | Redundant , reader already announces "image" | Remove the prefix |
| Alt over 125 characters | Screen reader may truncate or feel verbose | Shorten or use longdesc / aria-describedby |
Limits: what this auditor does not catch
This tool audits alt attribute presence and basic patterns in pasted HTML. It cannot judge whether an alt text is semantically accurate , only a human reviewer can confirm that alt="red car" actually describes the image. It does not load external resources, so images rendered by JavaScript after page load will not appear in pasted HTML. For a full accessibility audit, manual testing with a screen reader remains necessary alongside automated checks.
Alt text and UK SEO: Google Images indexing
Google indexes alt text to understand image content and rank images in Google Images search. UK e-commerce and editorial sites see measurable organic traffic from image search. A descriptive, keyword-relevant alt (without keyword stuffing) contributes to image SEO alongside the surrounding page context. Audit your alt text regularly as part of your content maintenance workflow.