The top 5 most common web accessibility issues detected when using an automated tool to test your website

February 10, 2022

The top 5 most common web accessibility issues detected when using an automated tool to test your website. There are many automated tools available to help identify how accessible your website is. So what are the top 5 issues you should look out for?

color wheelColour Contrast Ratio Issues

Ensuring all text (and other elements) can be read by everyone is an important part of web accessibility. For example, ensuring text and backgrounds contrast enough to be readable by people with reduced vision (who may not be able to distinguish between colours).

Colour contrast analysis tools allow you to see what areas are difficult for people with reduced vision to read, which can therefore help you make improvements for everyone.

Some tools are free, whereas others are not. One example of a colour contrast analysis tool is the Colour Contrast Analyser (which is free).

f scoreAutomated JavaScript Validation Issues

Some tools for checking web accessibility will attempt to validate your website for conformance to web standards and will report errors where problems exist. One such example is the free validator service at

Although standards compliance is a good starting point, it does not prove that your website is accessible. The W3C Validator does not attempt to test for accessibility issues, so you may need a different tool.

validationAutomated Flash Validation Issues

Although Adobe Flash is not a web standard, it’s still widely used for adding animation, video and interactivity to websites.

Many automated tools are able to check whether the Flash files on your website are accessible, for example by checking that they have a text equivalent or an accessible name.

Flash accessibility is a complex topic and it’s not as simple as checking for the presence of text.

For more information on checking your Flash files for accessibility, see WebAIM’s Flash Accessibility Tutorial.

textText Equivalents (Alt Attributes) For Images

All images should have an alt attribute which provides a textual description of the image. This is used to provide information for people with visual impairments who may not be able to see the image, for example.

Some automated checkers are able to detect whether your images have an alt attribute or not, including the free validator service at

htmlUsing the correct element for your purpose (e.g., using a map element instead of an image)

Not every type of content must be presented using the elements within HTML. For example, if you have a logo, you can use an image element and not bother with the hassle of creating an alt attribute!

Although it’s generally best practice to use HTML elements correctly, all content should have a text equivalent. This means that if your content is an image, you should provide it as well as an alt attribute.

Additionally, it’s good practice to ensure that the type of element you are using makes sense for your content. For example, if you are using a map element then your images should show the relevant location!

Summary Of The Top 5 Issues Detected By Automated Tools

There is a free colour contrast analysis tool that can be used to help you make your web content more accessible. Partner this with the free validator service at and you can ensure your web content is accessible to everyone!

Using the correct element for your purpose (e.g., using a map element instead of an image) is also important, but always remember to provide the content in another format (text) that sighted people using screen readers will be able to access.

Your web content should also have a text equivalent (e.g., alt attribute for images or a longdesc attribute for media elements), be compliant to web standards, and have an automated JavaScript validation issue.

If you’d like to learn more about web accessibility visit us at

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