Advancements in the technology and intelligence programmed into automated accessibility scans beg the question: is automated testing enough for accessibility and ADA compliance? In short, no — automated testing is valuable and should be part of your larger accessibility testing strategy, but it should not be used to replace human testing or prove compliance on its own.
What are the benefits of automated accessibility testing?
They vary by methodology and effectiveness, but all automated tests essentially perform the same function: scan web pages for accessibility violations. While not all automated scans are created equal, their value and importance center around:
- Speed: Automated scans tend to be fast – much faster than people – so they can quickly run through the code of a page or pages. If your website has a lot of pages, or very complex pages, automated testing can improve efficiency.
- Benchmarking: Running periodic automated scans of a website can be a great way to gauge what’s changed recently. If something new shows up that wasn’t found in previous tests, it’s a good indicator that you should investigate further to determine the accessibility impact.
- Catching obvious issues: There are some issues a good human tester will always find (things like missing alt text and missing labels on forms), and those are the same issues automated scans are best at finding. They still need to be validated by a person, but having a computer instantly identify some of the issues you’d have found anyway has obvious benefits.
What are the limitations of automated accessibility testing?
The most obvious and important shortcoming of automated tests is that they aren’t people — and people of all abilities, not machines, are using your site. Automated accessibility scans lack the subtleties and knowledge to identify the true accessibility of elements that will be used by people. As such, they are prone to generating “false positives” and overlooking certain types of issues.
Here are some of the most common issues that automated scans have trouble with:
- Inadequate alt text: Automated scans can quickly determine if an image has an alt attribute (the most typical way to account for alt text for basic images), but they can’t necessarily tell if the alt text is appropriate. If the alt text does not accurately describe the image, or if it tries to describe a decorative image that should be ignored by assistive technology, there is a clear accessibility violation that the scan won’t catch.
- Mislabeled elements: Like the alt text issue, there are certain elements on a page that require clear, helpful labeling. Automated testing may be able to identify whether a label is present, but may not know if that label serves its purpose.
- Inaccessible off-page links: Imagine this scenario: you’ve created a compelling web page with great content; you thoroughly tested and remediated for accessibility; and you link to some other website or asset that you think will be helpful for your visitors — but what if that linked resource goes to an inaccessible PDF or a video without a transcript and captions? Automated testing won’t tell you what happens on the other end of those links, but your site’s visitors should have the reasonable expectation that they can successfully follow your essential links.
- Inadequate keyboard focus indication: Users who have sight but navigate by keyboard or similar methods need to know which element on a page is receiving focus. To achieve this critical aspect of navigation and operation, a visible focus indicator needs to clearly identify whichever active element a user is currently selecting. Only a human tester can determine the sufficiency of visual focus.
- Failed color contrast ratios: Color contrast is essential to web accessibility and it’s measured by contrast ratios to determine if it is sufficient. Many automated tests will check for color contrast, but depending on how the page is built, they may not have all the information needed to identify problematic color combinations across-the-board.
Automated accessibility scans also can’t identify the most common or most important use cases on a website. Every page or element that is part of a key process or action is especially critical to a site’s accessibility, and only human evaluation can define and test those specific steps.
What is the best way to test for accessibility?
Automated testing is a great first step and can provide an overview into the general accessibility of your website. The best value of these scans comes when they are combined with human testing. That’s why we recommend a complete manual audit like our four-point hybrid testing.
Get started with a free and confidential website accessibility scan. When you’re ready, talk to us about all the ways we can help you achieve, maintain, and prove digital compliance.