The pitch is attractive: paste one line of JavaScript, a widget appears, and your accessibility problem is handled. No developer time, no audit, a compliance badge for the footer. If that worked, this article would say so, and we would sell you one.

It does not work, and the reasons are not a matter of opinion. They sit in how the standard measures a page, in what regulators have already done about the claims, and in what the users the law protects report about the widgets themselves.

What an overlay actually does

Two different things travel under the name "overlay," and separating them is most of the argument.

The first is a user-preference toolbar: font-size controls, contrast modes, animation pausing, a reading mask. As an optional extra, this is legitimate. Some users appreciate it, it harms little, and nothing in this article argues against offering one, as a feature.

The second is the compliance claim: that the same script detects and repairs your site's accessibility failures at runtime, and that installing it makes the site conform to the standard. This is the part that fails. The script repaints symptoms on top of the page for some issues it can guess at; your templates, forms, images and checkout remain exactly as they were.

What the standard actually measures

The EAA's technical yardstick is EN 301 549, which for web content incorporates WCAG 2.1 Level AA (the widely used checklist of web accessibility rules). Conformance is a property of the page as delivered to the user: the real markup, the real form labels, the real keyboard behavior. There is no provision in the directive, the standard, or any national transposition we map (Germany's BFSG, Czechia's zákon č. 424/2023 Sb., Poland's ustawa z 26.04.2024) that exempts a site because a repair script is loaded alongside it.

That has a practical consequence: anyone who checks, whether a market surveillance authority, a plaintiff's expert, or an automated scanner, tests the page underneath. Run a scan on a site with an overlay installed and the underlying findings are typically still there, because the code they live in was never touched.

What regulators have done about the claims

The clearest signal so far is from the United States: in January 2025 the FTC took action against accessiBe, the best-known overlay vendor, ordering a $1 million payment over misleading claims that its automated product could make any website compliant with the standard. The order targeted the compliance claim itself, the exact promise the one-line pitch is built on.

In the EU, enforcement is younger but running. Germany's market surveillance authority (MLBF) has been in an active control phase since January 2026 and can request your accessibility statement and the assessment behind it. An overlay subscription is neither of those documents. A statement that claims conformance because a widget is installed is worse than a missing one, because it is a checkable overclaim.

What the users the law protects report

The law exists for people who browse with assistive technology: screen readers (software that reads pages aloud for blind users), keyboard-only navigation, magnification. Practitioners and assistive-technology users have documented for years that overlays can actively interfere with the setups those users already run; the Overlay Fact Sheet, signed by hundreds of accessibility practitioners, collects the evidence and urges site owners not to treat overlays as a remediation. Some users go further and run browser extensions built specifically to block overlay scripts. A "fix" that part of its own target audience installs tooling to switch off is a poor foundation for a compliance argument.

The math that does not add up

Automated tooling, ours included, detects roughly 30–40% of WCAG criteria (source: Deque Systems' Automated Accessibility Coverage Report). That is the honest ceiling for anything that works without a human. An overlay can only attempt runtime repairs on a subset of *that* subset, and it guesses without seeing your intent: it can add *an* alt text, not the *right* alt text. Meanwhile the WebAIM Million project keeps finding an average of 56 detectable errors per home page across the web. The gap between what a script can patch and what the standard requires is not a rounding error; it is most of the standard.

The pattern to internalize is the same one from our six-step guide: if the fix could be a one-liner, the standard would say so. Real fixes happen in your templates and CMS, which is also where they are cheapest, because most shops fail on a handful of repeated, template-level issues.

If you have an overlay installed today

No panic is required, and ripping it out overnight is not the point. The sequence that actually reduces exposure:

  1. Scan beneath it. Run an independent check and see what remains in the underlying code. Our free website accessibility checker tests one page against WCAG 2.1 AA and shows the most serious finding with its legal reference.
  2. Reclassify the widget. Treat it as a user-preference feature if you want to keep it, and as neither fix nor evidence. Remove any conformance claim that rests on it.
  3. Make the statement honest. Your accessibility statement should describe the site's actual state, known limitations included. Our statement generator drafts one with every required part.
  4. Budget real remediation. Template-level fixes first; the six-step path is the playbook.

FAQ

Q: Our overlay vendor says the product makes us EAA-compliant. Who is right? A: Ask the vendor for an EN 301 549 assessment of *your site as delivered* with the overlay running, and compare it against an independent scan of the same pages. The FTC's 2025 order against accessiBe concerned precisely the gap between that kind of claim and what the product does.

Q: Is it wrong to offer a widget at all? A: As an optional user-preference toolbar, no. Some users like them. What fails is presenting it as remediation or citing it as evidence of conformance.

Q: Does an overlay at least reduce our risk while we fix things properly? A: What reduces exposure in a graduated enforcement procedure is documented remediation: an assessment, a prioritized fix log, an honest statement. An overlay produces none of those, and an overclaiming statement built on one adds a visible defect instead.

Q: Will a surveillance authority accept the widget as evidence? A: The documents an authority can request are the accessibility statement and the assessment behind it. A subscription receipt for a script is neither.

Sources

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Related article: From scan to statement: six steps to audit-ready accessibility

This article is informational and does not constitute legal advice.