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Should I use an accessibility overlay?

Due to their technical, social, and moral issues, The A11Y Project does not recommend using permanent overlay plugins. We view these kinds of products as actively harmful, and a step backwards for digital accessibility efforts.


Accessibility overlays have become a controversial topic recently. Let’s clarify what they are, and how they impact accessibility.

An accessibility overlay is JavaScript that is written with the goal of helping to fix accessibility issues on a website or web app. Overlay code is applied after the website or web app is rendered by the browser, to transform it.

Generally speaking, there are two types of accessibility overlays:

  1. Temporary bandage solutions, and
  2. More permanent plugins.

Of the two, the more permanent plugins are incredibly problematic.

Temporary bandage solutions

Temporary bandage solutions have been around for awhile. Historically, they have been used by professional accessibility auditing companies as a stopgap measure.

With the bandage approach, the overlay serves as a temporary measure. It is designed to be used to temporarily fix specific, critical accessibility issues until the underlying website or web app code can be updated.

Think of these kinds of overlays like a bandage. Bandages are not intended to be left on permanently. They are removed after the injury they cover has healed.

Bandage overlays usually have a process to signal when their code should be removed. This process is typically a negotiation between the accessibility auditors and the company who has the inaccessible experience.

Permanent plugins

Permanent plugins are more of a recent phenomenon. Unlike temporary bandage solutions, permanent plugins are designed to be a persistent presence on the inaccessible website or web app. Four examples of permanent plugins are accessiBe, AudioEye, FACIL’iti, and Max Access.

There are numerous issues with permanent plugins. To build off the bandage metaphor, a permanent plugin left on a website or web app for too long will cause the underlying experience to rot.


People are not a problem to be solved.

Ableism is a prevalent issue in society. Because of this, there is a lot of misunderstanding about disability, and how it intersects with digital experiences. Permanent plugins attempt to capitalize on this.

Permanent plugins are oftentimes sold to product managers and high-level decision-making employees as an “instant fix” to accessibility issues. They use the threat of a lawsuit as a compelling factor. This does two things. It:

  1. Leaves people who may be more familiar with digital accessibility practices out of the conversation, and
  2. Frames the entire experience as risk avoidance, as opposed to a way of ensuring access.


Broadly-speaking, there are two kinds of accessibility issues:

  1. Issues that are objective and can be detected by a set of programming rules.
  2. Issues that are subjective and require a human to evaluate.

An example of this is the alternate description of an image. Programming rules can check if an image has an alt attribute. However, programming rules cannot determine if the description is accurate, especially if the image is used for a thematic purpose.

Any permanent plugin that claims to automatically “fix” these kinds of issues cannot deliver on its promises. There are many lawsuits filed against permanent plugin companies reflecting this. Ironically, some permanent plugins actually introduce more accessibility issues when activated.


Temporary bandage solutions come with training, which help the website or web app design and development teams learn how to not repeat the same decisions that created the inaccessible experience.

Permanent plugins do not provide the accompanying training. This means that designers and developers will not grow skill-wise, and the same mistakes will be repeated over and over. If accessibility is viewed as “set and forget,” there is also a high likelihood that the scope of accessibility issues will increase exponentially.


Many permanent plugins override customization and personalization choices a person relies on. These overrides oftentimes do not meet the level of detail and sophistication needed, and may not operate in an expected way.


Privacy and disability are closely related. There are many concerns with being identified as an assistive technology user without consent. Some permanent plugin products do not disclose what they do with the information they collect, including selling the information to third parties.


Due to ableism and the discrimination it creates, there is unfortunately a strong correlation between disability, unemployment, and underemployment. Because of this, there is a decent chance assistive technology may be used on a more inexpensive, lower power device.

Permanent plugins run an extra “layer” of JavaScript over the experience. This slows down a website or web app, and in extreme cases may cause the entire thing to crash. The chance of crashing, or being slowed down to the point of being unusable increases on lower powered devices.


Malware is software designed to subvert and damage the system it is run on.

Certain permanent plugins include code that attempts to detect and negate automated accessibility-checking tools such as Axe or WAVE. This prevents someone from accurately auditing the actual state of their website or web app.

As they call code that is controlled by someone else, there is also the potential for control over this code to be hijacked. For example, the permanent plugin BrowseAloud was hacked to change its code to mine cryptocurrency.

Avoid using permanent plugins

Instead of using a permanent plugin, we encourage anyone who helps to make digital experiences to:

  1. Learn more about disability and how assistive technology works.
  2. Check your website or web app for accessibility issues.
  3. Test with a wide variety of assistive technology, and assistive technology users.
  4. Incorporate disabled people into your product creation process.

Further reading