Why accessibility overlays don't fix your website

If you run a website, you have probably seen the offer: add one line of JavaScript and a small accessibility icon appears in the corner. Click it and visitors can make text bigger, change colours or switch to a "screen reader mode". The marketing often adds that artificial intelligence repairs the rest of the site automatically.

These tools are called accessibility overlays. They are popular because they are quick and cheap. But they don't fix the problems that actually stop disabled people from using a website, and they can add new ones.

What an overlay does

An overlay is a script that runs in the visitor's browser after your page loads. It usually does two things:

1. Adds a toolbar with options such as bigger text, higher contrast, a readable font, stopping animations, or a built-in text-to-speech reader.
2. Tries to repair the page on the fly, for example by guessing alt text for images with AI, or adding ARIA attributes to elements it thinks are buttons or menus.

Why that doesn't fix your website

The toolbar repeats what people already have. Disabled people who need bigger text, higher contrast or a screen reader already use the settings in their browser and operating system, or their own assistive technology. They set it up once and it works on every site. A different toolbar on every website doesn't help them.

Automatic repairs are guesses. A script can't know that an icon button opens the cart, which form field is the delivery address, or what a chart is meant to show. AI-generated alt text often describes what's visible ("a person smiling") rather than what matters on that page. Complex parts of a site, such as menus, date pickers, product filters and checkouts, usually need changes to how they work, not labels added on top.

It can make things worse. Overlays change the page after it loads. That can conflict with screen readers, add a second, unexpected reading mode, and make keyboard navigation slower. Some overlays also detect whether a visitor uses assistive technology, which many people consider a privacy problem.

Your source code doesn't change. Remove the script and every problem is still there, because none of them was fixed where it lives: in your templates, components and content.

What disabled users and experts say

Hundreds of accessibility professionals have signed the Overlay Fact Sheet, which asks site owners not to rely on overlays. The US National Federation of the Blind has spoken out against them, and many blind and low-vision users say they turn overlays off or leave sites that have one.

Regulators have noticed too. In January 2025 the US Federal Trade Commission reached a $1 million settlement with one overlay vendor over claims that its AI tool could make any website meet WCAG. Lawsuit trackers also count hundreds of US accessibility lawsuits each year against websites that had an overlay installed.

What to do instead

The work that actually helps is less mysterious than it sounds:

1. Find the real problems. Run an automated check, like our free checker above, and do the 2-minute keyboard test.
2. Fix them in the source. Most problems sit in a few templates: the header, navigation, footer, product page and forms. Each fix there repairs every page that uses it.
3. Start with the six most common problems. Contrast, alt text, form labels, link names, button names and page language. We go through each one in the 6 accessibility problems on almost every website.
4. Test with real assistive technology. Try a free screen reader (NVDA on Windows, VoiceOver on Mac and iPhone) on your key pages, or ask disabled users for feedback.
5. Keep checking. Every new feature and theme update can bring new problems, so scan again after changes.

Automated tools, including ours, find only part of the problems. The difference is what happens next: a fix in your code helps every visitor, with their own setup, every time.

Have you been offered an overlay, or do you use assistive technology and have a view on them? Tell us in our Website Accessibility Help group.