Website accessibility and agent-friendly sites

Spencer Thursfield · Published 2026-09 · Last reviewed 2026-09-12 · Evidence: standards and platform documentation

Website accessibility means building a site so that disabled people can perceive, understand, navigate and interact with it. In practice it comes down to a few habits: real text, headings in order, labelled controls, described images and links that say where they go.

Several of those habits are also what Google asks for when it explains how its own systems read a page. How far they help AI agents is a smaller claim, and this page labels each step of it.

What is website accessibility?

The W3C’s Web Accessibility Initiative defines it as websites, tools and technologies “designed and developed so that people with disabilities can use them”. It covers auditory, cognitive, neurological, physical, speech and visual disabilities.

The same page notes who else gains, including people on small screens, older people, and anyone with a broken arm or lost glasses.

What are the Web Content Accessibility Guidelines?

The Web Content Accessibility Guidelines, WCAG for short, are the W3C standard that most accessibility rules point to. The current version, WCAG 2.2, became a W3C Recommendation on 12 December 2024. The standard itself is the authority, and the W3C’s WCAG at a glance is the shortest faithful summary.

At the top sit four principles:

• Perceivable. People can take the content in. Text alternatives and captions belong here.
• Operable. Everything works from a keyboard, and people have enough time to use it.
• Understandable. Text is readable, pages behave predictably, and forms help people avoid and correct mistakes.
• Robust. Content “can be interpreted by a wide variety of user agents, including assistive technologies”.

Under them sit 13 guidelines and, under those, testable success criteria. Each criterion has a level: A (lowest), AA and AAA (highest). A page that meets AA meets every A and AA criterion. GOV.UK tells public sector bodies that their websites meet the legal requirements if they meet WCAG 2.2 AA and publish an accessibility statement.

Does a small business have to meet WCAG?

The regulations that name WCAG 2.2 AA apply to public sector bodies. Private businesses sit under a different duty, written as reasonable adjustments rather than a technical standard. GOV.UK: “All UK service providers have a legal obligation to make reasonable adjustments under the Equality Act 2010 or the Disability Discrimination Act 1995 (in Northern Ireland).”

Section 29 of the Equality Act says a service provider, paid or not, must not discriminate against a person requiring the service, and applies the duty to make reasonable adjustments to service providers. Section 20 says the steps can include making sure “the information is provided in an accessible format”. What is reasonable depends on the circumstances. This is not legal advice; ask a solicitor about your own position. Context-dependent

Six checks you can do in ten minutes

Each comes from a WCAG criterion or the W3C’s Easy Checks. Try them on your homepage and your busiest page.

1. Headings. One main heading, then sections in order, never jumping from level 2 to level 4. The W3C notes that screen reader users often navigate a page by its headings. (WCAG 2.4.6, AA.)
2. Image descriptions. Every meaningful image needs alt text, “a short description that conveys the purpose of an image” in the W3C’s words. A decorative one should be marked so assistive technology can ignore it. (1.1.1, A.)
3. Link text. Read your links out of context. A link reading click here says nothing; opening hours and prices does. (2.4.4, A.)
4. Colour contrast. Normal text needs a contrast ratio of at least 4.5:1 against its background, large text at least 3:1. (1.4.3, AA.)
5. Forms. Every field has a label saying what to enter. (3.3.2, A.)
6. Keyboard. Put the mouse aside and press Tab. You should reach every link, button and field, and see where you are. (2.1.1, A; 2.4.7, AA.)

The W3C is candid: such checks “cover just a few accessibility issues”, and a page “could seem to pass these checks, yet still have significant accessibility barriers”.

Does accessibility help AI read your site?

Partly. The evidence comes in three strengths.

What Google documents

Google’s guidance for its AI features asks site owners to make sure “important content is available in textual form”. Its image guidance says alt text “also improves accessibility for people who can’t see images on web pages”, and that Google uses it alongside computer vision to understand an image. Its link guidance says link text “tells people and Google something about the page you’re linking to”. On text, alt text and link text, the accessibility advice and Google’s advice for its own systems are the same advice. Official recommendation

Text only counts if a machine receives it; words that appear only after scripts run are covered in static HTML and JavaScript rendering.

What the standard says about software

WCAG was not written for screen readers alone. It defines a user agent as “any software that retrieves and presents web content for users”, and criterion 4.1.2 asks that every form field, link and scripted control has a name and role that can be “programmatically determined”: read by software from the markup.

The agent link, which is our inference

AI systems now visit pages on a person’s behalf. OpenAI documents that when someone asks ChatGPT a question, “it may visit a web page with a ChatGPT-User agent”. An agent that has to find a booking form and press the right button is doing what WCAG calls a user agent’s job, and a button with no name gives it nothing to go on.

That last step is reasoning, not a published fact. No operator documentation we could retrieve on 12 September 2026 says how an agent reads a page or whether it uses accessibility information. OpenAI’s help pages about its agent refused our automated requests that day, so we cite nothing from them. Emerging

Where the overlap stops

Colour contrast and keyboard focus serve human eyes and hands; nothing we read suggests a crawler weighs either. Nor is accessibility a documented entry ticket: for AI Overviews and AI Mode, Google says “there are no additional technical requirements” beyond being indexed and eligible for a snippet. And a page no crawler can fetch helps nobody, which is why whether AI can reach your site comes first. Make a site accessible because people need it. Context-dependent

How do you test a site properly?

Automated checkers are the fast first pass. The W3C keeps a list of evaluation tools and states that it “does not endorse specific products”. Two you will meet are WebAIM’s WAVE, which says it finds WCAG errors and “facilitates human evaluation”, and Google’s open-source Lighthouse, which has accessibility audits and runs in Chrome DevTools.

Treat a clean score with care: Lighthouse’s own scoring notes say manual audits do not affect it. Then do what tools cannot. Use the site by keyboard alone, and ask someone who relies on a screen reader what they hit.

What we do not know

Whether accessible pages are cited more often in AI answers. We have found no published evidence either way and have not measured it ourselves. Our method and pre-registration sets out what the benchmark does record.

Common questions

Which WCAG level should a small business aim for?

Level AA. It is the level GOV.UK sets for public sector websites, and it includes every level A criterion.

Does a UK small business legally have to meet WCAG?

The regulations that name WCAG 2.2 AA cover public sector bodies. GOV.UK says all UK service providers must make reasonable adjustments under the Equality Act 2010, or the Disability Discrimination Act 1995 in Northern Ireland. This is not legal advice.

Does an accessible website get cited more by AI?

No published evidence shows it. Google’s advice on text, alt text and link text matches accessibility advice; any wider benefit to agents is inference.

Can an automated checker tell me my site is accessible?

No. The W3C says quick checks cover only a few issues, and a page can pass them yet still have significant barriers. Test with a keyboard and with real users too.