Overlays and widgets promise fast accessibility. They do not change your underlying code. WebAIM found 67% of practitioners rate overlays “not at all” or “not very” effective, rising to 72% among respondents with disabilities. EDF and IAAP warn overlays interfere with assistive technology and override user settings.
What overlays are
A third party script injects an extra interface into your pages.
You get a floating button with controls for text size, contrast, fonts, and similar toggles.
Some vendors claim automated “AI remediation”.
- They run after page render.
- They change the surface, not the foundations.
- They add another UI layer for users to deal with.
Red flags in sales pitches
- “One line of code”.
- “Instant WCAG compliance”.
- “AI fixes everything”.
- Badges, certificates, and dashboards based on automation counts.
Why they fail
Accessibility relies on structure, semantics, content quality, and predictable behaviour.
Overlays do not fix those fundamentals.
- Automation misses context, especially alt text, link purpose, error handling, and task flow.
- Users already rely on their own assistive tech and settings.
- Overlays override user settings and interfere with assistive tech.
- Teams stop funding remediation once an overlay badge goes live.
What I do instead
I prioritise fixes that remove blockers in real journeys.
- Audit key journeys against WCAG 2.2 AA.
- Fix templates, components, and content at source.
- Retest with keyboard and screen readers.
- Publish an accessibility statement with a feedback route and response process.
Evidence and sources
This topic attracts strong marketing claims.
This page links to primary and disability-led sources.
- Read the full article with source footnotes: /writing/accessibility-overlays/.
- See the accessibility service page: /services/accessibility/.
Relevant work
Rough pricing
This work usually falls into one of these routes:
- Kickstart: £99 setup + £69/month (24 months) or £89/month (12 months)
- Support Scheme: from £600 + £25/month
- Straight-up Build: from £1,200
If your site needs deeper changes than fixes allow, you will get a clear steer.
FAQs
Do overlays make a site WCAG compliant?
No. They do not fix the underlying code and content. They often add new barriers.
Do overlays help screen reader users?
Not reliably. Screen readers depend on correct semantics, labels, roles, and states in the underlying interface.
What is the fastest route to improvement?
Pick high value journeys. Fix the biggest blockers. Roll fixes into shared components. Retest.