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What to Know About Accessibility Checker Browser Extensions

Apr 18, 2023

Can you test your website’s accessibility by installing a simple web browser extension? 

Not necessarily — but you can test for specific web accessibility issues, which can help you make decisions that accommodate users with certain disabilities. 

In recent years, various accessibility tools have become available through Google’s Chrome Web Store and Mozilla’s Firefox Add-Ons marketplace. Some of the tools work quite well, but it’s important to understand their limitations before using them for an accessibility audit. Here’s why.

Accessibility browser extensions have the same drawbacks as other automated tests

The international standards for digital accessibility are the Web Content Accessibility Guidelines (WCAG), which are published by the World Wide Web Consortium (W3C). The W3C also maintains standards for HTML, CSS (Cascading Style Sheets), and other internet essentials. 

WCAG includes dozens of success criteria, pass-or-fail statements that can be used to test web pages (along with mobile content, web-delivered documents, and other types of digital content). However, many success criteria rely on human judgment.

While artificial intelligence (A.I.) has come a long way, machine models aren’t yet capable of exercising human-like judgment. That means that automated tests can miss many barriers that affect internet users who have disabilities. For example: 

  • WCAG requires images to have alternative text (also called alt text or alt tags). Automated tests can determine whether alt text exists, but not whether it accurately describes your visual content.
  • WCAG requires accurate captions for multimedia. Automation can confirm that captions exist, but cannot determine whether captions are properly synced with the video. 
  • WCAG requires descriptive, unique page titles. Once again, automated tools can determine whether your page titles meet certain guidelines, but not whether they describe the content of the page.

These aren’t minor issues — remember, the goal of accessibility is to improve experiences for real people. If you don’t involve real people in the testing process, your results will be limited (and your users may feel frustrated). 

Related: Is Automated Testing Enough for Accessibility Compliance?

Automated audits are still valuable, particularly for certain types of issues

This isn’t to say that automation is useless. In fact, the W3C recommends automated tests as part of a conformance audit, and the Department of Justice (DOJ) recommends the same hybrid approach for testing web compliance with the Americans with Disabilities Act (ADA). 

But humans can understand nuance; machines cannot (so far). In web accessibility conversations, the details are important.

A human tester with a vision disability may be able to tell you how a certain issue affects their experience and help you find the best way to fix it. They can determine whether alt text is descriptive enough for a typical user, or whether your subheadings are accurate to your content. 

Related: What’s the Difference Between Manual and Automated Accessibility Testing?

So, are web accessibility browser extensions actually useful?

Absolutely — as long as you understand their limitations. At the Bureau of Internet Accessibility, we use automated tools regularly as part of our hybrid testing methodology

Automated tests are ideal for finding WCAG conformance issues that fail simple pass-or-fail rules. For example:

There’s another reason to include automation in your accessibility compliance strategy: Manual tests can only measure your website’s accessibility at a specific point in time. Automated tests can provide realtime feedback, which can be crucial for long-term conformance.

Related: How to Check WCAG Compliance: A Quick Guide

For best results, pair automated accessibility tests with human testing

Automation has played an important role in the digital accessibility movement. Over the next several years, we expect A.I. tools to continue to improve, simplifying the work of inclusive design — but because the goal is to improve human experiences, human guidance will always be essential. 

Here are a few tips to keep in mind when using accessibility browser extensions: 

  • Beware of any browser extensions that promise “guaranteed" results. No automated test can determine whether your website conforms with WCAG — or verify compliance with the ADA or other accessibility laws.
  • Remember that other browser extensions may conflict with a web accessibility checker. Additionally, some extensions may not work well on complex content (such as desktop-like web apps). 
  • Prioritize web accessibility when developing your website. Don’t wait to fix issues after launch; by that point, accessibility barriers may already impact your audience. 

To measure your website’s current level of conformance, try our free, confidential website analysis. From there, you’ll still need manual testing for sustainable digital compliance — but by starting with automation, you may be able to quickly fix many of the basic issues that affect your audience.

Use our free Website Accessibility Checker to scan your site for ADA and WCAG compliance.

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