Why Automated Testing For Accessibility Is Not Enough

October 2, 2018

According to Gov.uk, running automated accessibility tests on your website is similar to running your document through spell check. It will catch obvious spelling errors, but if you wrote the word ‘cat’ when you actually meant to write the word ‘bat,’ spell check won’t flag that as an error. That’s because spell check isn’t built to scan your writing for context or clarity. 

So, unless you proofread your documents manually, you could end up with some nonsensical sentences. 

When testing your site for accessibility, automated testing can be useful for analyzing large chunks of code, and can provide a baseline of issues that need to be investigated further. 

However, like spellcheck, automated testing for accessibility will not ensure that your website is translating the context of your content clearly to those with a disability. 

Here are some of the reasons why automated testing for accessibility is not enough.

Alt text

The primary purpose of alt text is to describe the images on a page to users who are visually impaired. Adding alt text to your HTML code provides a text alternative to images that can be read out loud by screen readers.  

Brown puppy sitting in green grass

For example, for the image above, alt text could look something like this:

<img src="puppy.png" alt="puppy"> 

Technically you’ve written alt text for the image, but the word “puppy” doesn’t describe the image entirely. Instead, you might write something like:

<img src="puppy.png" alt="Brown puppy sitting in green grass">

This alt text is better than the first example because it’s much more descriptive. However, if you were to run the first line of code through an automated accessibility testing tool, it would not be flagged.

Automated testing isn’t intelligent enough to know if the alt text is descriptive or not, it’s only checking to see if it exists. 


An accessible online form is crucial. Labels can easily be associated with form fields within the site’s code for users with visual disabilities. By including labels within HTML, you allow those who use screen readers to navigate the form easily. 

However, similar to alt text, it’s important that labels are both descriptive and accurate. While automated testing tools can determine if labels are missing, they’re not sophisticated enough to judge whether the labels are particularly helpful. 

It’s also important to consider users who will navigate your site with a keyboard. As a user tabs through a form, sections should be highlighted so it’s obvious where they are within the form. This is especially true for complex forms that contain multiple options like checkboxes and drop-down menus. 

Rich media

Rich or interactive media is best described as media that can be downloaded or embedded into a webpage. Multimedia such as videos or online games are both examples of rich media.

This type of dynamic content cannot be scanned using automated accessibility testing tools and requires human testing to ensure it’s accessible. 

Videos should include closed captioning for the hearing impaired. Audio files should include text descriptions for individuals who are visually impaired and rely on screen readers. 

Automated testing for accessibility can speed up the QA process by analyzing large quantities of code while identifying major issues, but you should never rely solely on automated testing. It doesn’t account for issues that are subjective in nature, which is why a thorough accessibility audit requires manual testing as well. 

Finding a balance of automated and manual testing ensures that your website meets current accessibility standards and is equally accessible to all individuals.