Overlay widget
- Sits on top of the page as an extra layer
- The code underneath stays as it was
- No evidence that any criterion is met
Real fix
- Problems are fixed in the code
- Works with the tools people already use
- Every criterion decided by a person
What an overlay actually does
An overlay is third-party code, usually JavaScript, that you add to your site with a single line. It runs in each visitor’s browser after the page has loaded. Most show a toolbar with options such as bigger text, colour changes or read-aloud. Some also claim to repair code problems automatically, for example by generating missing alt text.
What it never does is change your own source code. It tries to patch the finished page on the fly, every time, in every browser.
Why that is not enough
WCAG sets requirements for the content itself. Does each image have a fitting text alternative (1.1.1 Non-text Content)? Is every form field labelled (3.3.2 Labels or Instructions)? Can everything be operated by keyboard (2.1.1 Keyboard)? A page conforms only when it meets every criterion at the chosen level.
Automated repair cannot get there. The Overlay Fact Sheet, signed by accessibility practitioners worldwide, documents that automatic alt text, fixes to labels, error handling, focus control and keyboard access are not reliable. Component-based interfaces that update with JavaScript can change underneath the overlay faster than it can react. Since conformance means meeting all requirements, a product that cannot fix all issues cannot make a site conformant.
Disabled users already have their own tools
People who use a screen reader, a magnifier or voice control have set it up on their own device, for every website and app they use. Browsers and operating systems already offer zoom, high-contrast modes and text-to-speech.
The Fact Sheet calls overlay toolbars redundant at best. A joint statement by the European Disability Forum (EDF) and the International Association of Accessibility Professionals (IAAP), published on 17 May 2023, goes further: overlays can override users’ own settings and make content harder, or impossible, to reach. The Fact Sheet also raises privacy: detecting that assistive technology is running reveals something about a person’s disability.
What disability groups, the EU and the FTC say
- EDF and IAAP (May 2023): overlays do not make a website accessible or compliant with European accessibility legislation, and are no substitute for fixing the site itself.
- European Commission: its web accessibility page says overlays, and other tools that do not make the website itself meet the standard’s criteria, are not an appropriate solution, and that issues should be fixed at the source. It links to the Fact Sheet, which it says nearly 900 accessibility experts have signed.
- US Federal Trade Commission: in January 2025 the FTC announced an order requiring an overlay vendor to pay USD 1 million. It alleged that claims that the company’s AI tool could make any website WCAG compliant were false, misleading or unsubstantiated, and that paid reviews had been presented as independent opinions. The order became final in April 2025 and bars such compliance claims without evidence.
What works instead
- Fix the code. Real headings, labelled forms, enough contrast, full keyboard support. Every assistive technology benefits at once, and the fix stays.
- Scan early and often. Automated checks catch many issues fast. Start with your home page: run a free check.
- Have people test it. Only a person can judge whether alt text fits or a flow makes sense, ideally with a screen reader and with people who use assistive technology every day.
- Keep watching. Every new page can bring new issues. Regular scans flag regressions.
We do not install overlays and never count one as a fix. We test your site as it is delivered. Our test method explains how.
Frequently asked questions
Is it harmful to keep the widget as an extra?
It can be. EDF and IAAP warn that overlays can override users’ settings. It also suggests the site is already accessible when it may not be.
Can I get your certificate with an overlay installed?
An overlay never replaces a passed criterion. We test the delivered content; a criterion that only passes thanks to a widget is marked as failed.
Are all accessibility tools bad?
No. Testing tools that find issues and show them to your team are very useful. The problem is products that promise to hide issues in the browser instead of fixing them.
Sources
How does your website do?
The free check tests your home page in two minutes. The audit decides all 55 criteria, by a person.