Overlays are not the solution to your accessibility problem

In the long run they will hurt, not help your approach to people with disabilities

Sheri Byrne-Haber, CPACC


Authors note: Because of Medium’s refusal to address its accessibility issues for both authors and readers, I’ve moved my last three years of blogs to Substack. Please sign up there for notices of all new articles. Also, I will be updating older articles (like this one) and the updates will only be published on Substack. Thank you for your continued readership and support.

Accessibility overlays are tools that detect and dynamically repair HTML accessibility issues in non-mobile environments. And what accessibility manager in their right mind WOULDN’T want a solution that does that? Write an annual check and presto change-o your site is accessible which means you don’t get sued. Unfortunately that’s a little too good to be true.

How can you fix what you can’t detect?

The industry is largely in agreement that only 30ish % of accessibility issues can be detected through code analysis. That means 70 % of accessibility issues can’t even be *detected* via code analysis much less fixed.

How can an overlay:

  • Make an non-responsive website responsive
  • Take an image with embedded text and make it magnify appropriately
  • Shorten a two paragraph non-navigation header into something meaningful
  • Determine whether or not a picture is decorative, for the determination of whether alt text should be null

Simple answer — it can’t.

Overlays lull stakeholders into thinking they don’t have to care about accessibility

This is a continuation of problem #1. It just isn’t feasible for an accessibility overlay to fix everything. But it makes the overlay buyer “think they’ve taken care of that pesky accessibility issue” and as a result, of course they don’t need to spend any more time or $$ on accessibility.

Overlay vendor’s guarantees are meaningless



Sheri Byrne-Haber, CPACC

LinkedIn Top Voice for Social Impact 2022. UX Collective Author of the Year 2020. Disability Inclusion SME. Sr Staff Accessibility Architect @ VMware.