Accessibility and SEO

Accessibility and SEO describes the overlap between making a website usable for people with disabilities and making it understandable to search engines. Many accessibility practices, such as clear headings, descriptive links and text alternatives for images, also help crawlers and AI tools interpret a page.

Written by Paul Hoda, SEO consultant since 2005. Last updated 8 November 2026.

What web accessibility means

Accessibility means people can use a website regardless of disability. That includes people who are blind and use screen readers, people with low vision, people who are deaf, people who navigate by keyboard only, and people with cognitive or motor impairments.

The main standard is the Web Content Accessibility Guidelines (WCAG), published by the W3C. Version 2.2 is the latest. Many organisations aim for level AA. In the UK, the Equality Act 2010 requires service providers to make reasonable adjustments, and public sector websites have specific accessibility regulations.

Where accessibility and SEO overlap

  • Heading structure: logical header tags help screen reader users jump between sections and help search engines understand page structure.
  • Alt text: alt text describes images to blind users and gives search engines context for image search.
  • Descriptive links: anchor text like delivery times is clearer than click here for both screen readers and crawlers.
  • Semantic HTML: using real buttons, lists, tables and nav elements makes the page easier to parse for assistive technology and bots alike.
  • Transcripts and captions: text versions of video and audio help deaf users and provide indexable content.
  • Page titles and language: a clear title tag and a lang attribute help screen readers and search engines alike.
  • Readable content: plain language and good readability help users with cognitive impairments and everyone else.

Is accessibility a ranking factor?

Not directly. Google has not said it uses accessibility scores, such as the one in Lighthouse, as a ranking signal. The connection is indirect: accessible pages tend to be well structured, easier to crawl and more pleasant to use, which supports the things search engines do reward.

Some accessibility needs, such as colour contrast or keyboard focus styles, have little SEO effect at all. They are still worth doing because they make the site usable for real people and reduce legal risk.

Where to start

  1. Run an automated check with Lighthouse or a browser accessibility extension to catch obvious issues.
  2. Fix missing alt text, empty links, missing form labels and poor colour contrast.
  3. Check heading order: one clear H1, with H2s and H3s in a logical outline.
  4. Try using the site with only a keyboard: can you reach and use every link, menu and form?
  5. Test key pages with a screen reader such as VoiceOver or NVDA.
  6. Make sure pop-ups and intrusive interstitials can be closed by keyboard and announced properly.

Automated tools catch only some issues, so manual testing remains essential.

Common mistakes

  • Stuffing keywords into alt text, which makes screen readers read out spam.
  • Using styled divs instead of headings or buttons.
  • Relying on accessibility overlay widgets as a complete fix: they do not repair underlying code.
  • Text embedded in images with no text alternative.

Key Takeaways

  • Accessibility means people with disabilities can use a website fully.
  • Clear headings, alt text, descriptive links and semantic HTML help users and search engines.
  • Google has not said accessibility scores are a direct ranking factor.
  • Accessible sites tend to be better structured and easier to crawl.
  • Combine automated checks with keyboard and screen reader testing.

Related Terms

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