Overlays are not the solution to your accessibility problem

Four blue square layers falling on each other

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

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

If the seller guarantees 100 % accessibility, or they will cover your costs if you get sued, check the fine print very carefully. I’ve seen guarantees that took the form of an insurance policy good for covering up to 100K in legal costs, which is NOWHERE near the cost of the average accessibility suit when you consider:

  • Reputation / Brand Harm
  • Legal costs (internal, outside counsel, plaintiff’s lawyer)
  • Expert witness costs
  • Mediation / arbitration costs
  • Accessibility opportunity costs
  • Engineering opportunity costs
  • Settlement payment
  • Post-Settlement mandated costs
  • Tag along lawsuits

Overlays address the symptoms of the problem without treating the root cause

Overlays end run accessibility, rather than solving the actual problem.

The root cause of accessibility defects is stakeholders not caring enough to undertake the education and process changes that are necessary to create accessible products.

The overlays may mask some of the more egregious accessibility violations but they will never fix the cause of the inaccessibility which is lack of accessibility training and process for anyone who touches the software development life cycle.

Overlays never “solve” the problem the way the USERS want it solved

Overlays effectively force all your users with disabilities to learn yet another $#(*@$#@ accessibility tool rather than be able use their own setup that they’ve spent years customizing to their individuals needs.

Overlays only “work” in the web world, when the world is moving to mobile

If you don’t realize that mobile is more important than web, here are a few statistics

  • 55 % of email is opened on mobile first, almost 2:1 over web mail
  • Mobile is responsible for more than 40 % of global Internet traffic, peaking at over 60 % in China
  • 37% of in-store retail sales are influenced by a shopper using a mobile device
  • 52% of customers are less likely to engage with a company because of bad mobile experience. That’s ALL customers, not just customers with disabilities. 91 % of UK shoppers with disabilities said they had bailed out of inaccessible experiences for a competitor.

Overlays may impact security and performance

For an overlay to work, a call to a java script typically must be made from the top of the inaccessible HTML code (which is usually the home page).

  • That means your company will have to provide access to the home page code to the overlay company to “inject” a call to its solution
  • Which in turn means your home page security and performance is directly tied to the overlay vendor’s security and performance.

If that overlay script gets hacked, your site could be hosed.

If the overlay site’s performance is slow, your performance will be slow.

While the overlay company may be able to produce documentation that their servers are up to date on all security patches and vulnerability assessments, believe me, that’s a whole lot of paperwork the buyer has to keep track of quarterly. And that’s without taking into account currently threatened global hostility that may increase cyber attacks.

In the end, overlays will not be sufficient to avoid lawsuits and legal judgments

Say you (or your boss) have gotten this far into my article and still wants to use the overlay. You are going to end up in one of two situations:

  1. (Most Likely) The overlay doesn’t solve all the problems, you aren’t compliant, and you could get sued, or;
  2. (Likelihood of slim to none) The overlay does solve all the accessibility issues

Even if you somehow manage to end up with the miracle (the overlay solves every accessibility problem ever) it is quite possible your organization STILL gets in trouble. The Scandinavian airlines case from the DOT documents that at least one branch of the federal government isn’t buying overlays as accessibility solutions. Separate but equal is always separate, but never equal. And what is an overlay but separating your customers with disabilities from your customers without disabilities?


If overlay tools were the solution to everyone’s accessibility problem 100 % of the time, the accessibility consulting companies who actually know what they are doing would have created them already. Instead, they are coming from little tools companies who have limited experience with hands on accessibility testing or defending inaccessibility in litigation.

The only time it is even remotely OK to use an overlay is as a temporary stop-gap measure while remediating as fast as you can.

Remember, if it seems too good to be true …

… it probably is

And accessibility overlays are no exception to that rule.

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