Let us settle the headline claim first, because a lot of accessibility marketing overstates it and the overstatement is easy to check.
Accessibility is not a Google ranking factor. Google has never listed WCAG conformance as a signal, and its own documentation on ranking systems does not mention it. Anyone telling you an audit will lift your rankings is selling past what is known.
The truthful version is more useful anyway. Accessibility and search optimisation ask for the same work on eight specific things, because both are about something other than a person reading your page. The overlap is real and the analogy has a limit worth knowing. Google renders your page in Chromium and judges what comes out, so it is not blind to your layout the way a screen reader is. Where the two genuinely meet is that both lean on your markup to work out what a thing is.
The Eight Places They Ask for the Same Thing
| What | Why accessibility needs it | Why search needs it |
|---|---|---|
| Alt text | Screen readers announce it in place of the image | One of the signals used to understand and index an image |
| Real heading structure | Screen reader users navigate by heading | Headings signal what the page is about |
| Descriptive page titles | Announced first when the page opens | A main source for the clickable line in results, not a guarantee of it |
| Meaningful link text | Links get read out of context, where "read more" carries nothing | Anchor text tells crawlers what is on the other side |
| Semantic HTML | Native elements carry role and state for free | Structure a parser can follow |
| Video captions and transcripts | Deaf and hard of hearing users need them | Turns speech into text on the page, which is what a crawler can read |
| Working responsive layout | Low-vision users browse zoomed to 400% | Google indexes the mobile version of your page first |
| Clear, plain writing | Cognitive accessibility depends on it | Readable pages hold attention longer |
Eight items, one body of work. If you have been meaning to do the SEO housekeeping, you have been meaning to do most of the accessibility housekeeping.
Where They Part Company
The overlap has an edge, and pretending otherwise is how people end up disappointed.
Accessibility work that does nothing for search: colour contrast, visible focus indicators, keyboard operability, target sizes, motion and animation controls, seizure safety, time limits, error message wording, ARIA on custom widgets, and the page language attribute. That last one surprises people. Google's own documentation says it works the language out from the visible text and ignores the lang attribute, so as a Google play it does nothing. Other engines and translation tools do read it, and screen readers depend on it. Your users notice all of these, every day.
Search work that does nothing for accessibility: backlinks, page speed as a number, structured data markup, canonical tags, keyword targeting, and the XML sitemap you feed to crawlers. That last one comes with a caveat. A sitemap page written for people is a different object, and it is one of the accepted ways to give readers a second route to any page.
The two disciplines share a foundation and then go their own way. Buy an audit for the accessibility, and take the overlap as change from the same purchase.
The Second-Order Effects Worth Naming
Beyond the direct overlap, two things follow that are worth naming plainly.
Customers you already have, finishing what they started. The World Health Organization puts the number of people living with a significant disability at 1.3 billion, about 16% of the world. That is a population estimate rather than a forecast of your traffic, and nobody can turn it into a number for your site. What it does tell you is the shape of the risk. If your checkout cannot be completed by keyboard, that is not a ranking problem. It is a conversion problem, and it is happening to traffic you already paid for.
Fewer of the frustrations everyone shares. Unlabelled form fields, vague error messages, and links that say "click here" confuse plenty of people without disabilities too. Fixing them shows up in completion rates rather than rankings.
The honest pitch
We will not promise your rankings will move, because we cannot know that and Google has not said it. What we can say is that eight of the fixes in your report are ones your SEO consultant would have asked for anyway, so the same money buys both.
Where to Start on the Overlap
If you want the fixes that pay twice, do these four first:
- Fix your headings. Real heading elements instead of big bold text, in an order that matches how the page is actually built. A single h1 is a good habit and it is not a WCAG rule, so do not file it as a failure. Google reads your headings to work out what the page is about, and it has said out-of-order levels make no difference to Search, so put them in order for the screen reader rather than for the ranking. Our heading structure checker shows the outline a screen reader hears.
- Fix your alt text. Not filenames, not "image of". Our alt text checker catches the classic failures, and the decision helper settles what to write.
- Fix your link text. Every "read more" and "click here" becomes what is actually on the other side. The AA rule lets a link lean on the context its markup gives it, so some of these already pass. They still read as nothing in a list of links, and rewriting them costs a minute.
- Add captions and transcripts to video. Which of the two you owe depends on the media and the level, and captions on prerecorded video with sound are the Level A floor. Both turn audio into text that can be indexed.
Then run the free 10-page scan for the mechanical picture, and read our post on whether accessibility helps SEO for the evidence behind the claims on this page.
One honest limit
We audit accessibility. We do not do SEO, we do not measure rankings, and we will not tell you what your traffic will do afterwards. What we will hand you is a report that happens to fix eight things your search consultant has probably been asking for.