There are a variety of tools to assist you in performing an accessibility self-evaluation of your website or other digital content. Understanding the types of tools available to you, and their respective strengths and limitations, will help you choose appropriate tools to help streamline the testing process.

Automated Testing Tools

Automated testing tools are useful as easy, first-pass methods to identify the biggest accessibility issues. It’s important to understand that all automated testing tools are imperfect. The best tools will catch about 33% of errors, and automated testing tools produce both false positive and false negative errors.

Automated testing tools are good for catching the following types of errors:

  • Missing alt text on images
  • Missing captions on videos
  • Color contrast with solid-colored text against solid-colored background
  • Select heading hierarchy issues (ex. That there is exactly 1 <h1> per page)
  • Tables missing headers
  • Form fields missing labels

Automated testing tools are inconsistent or entirely unable to catch the following types of errors:

  • Anything to do with quality of content – quality of alt text, quality of video captions
  • Color contrast against a pattern background, an image background, or a video
  • That images and videos are free of text
  • Correct heading structure
  • Anything with keyboard navigation
  • Anything with text resizing
  • Anything with hosted files like PDFs

Recommended Automated Testing Tools:

SiteImprove – a free browser plugin for Chrome and Firefox that detects issues on the current page with a single button click. Has a simple interface.

WAVE toolbar – a free browser plugin for Chrome and Firefox that detects issues on the current page with a single button click. Similar to SiteImprove, but it also adds icons to the page where the accessibility issues can be found. This creates a slightly busier interface, but may help people identify the exact areas of their page that require attention.

Built-In automated accessibility testing tools in content-authoring software – MS Office products including Word, Excel, and PowerPoint, as well as Adobe Acrobat and other platforms, have built-in accessibility testing tools. These share the same limitations as website-testing applications, but can be useful to identify problems before they get shared to a wider audience.

Color Contrast Tools

While automated testing tools are adept at identifying some color contrast issues, they don’t typically tell you what colors you should use if the current color contrast is insufficient. There are a variety of web-based and desktop software to tell you the current color contrast, and provide suggestions for different colors that meet different tiers of contrast requirements.

Recommended Color Contrast Tools:

WebAIM Color Contrast Checker: A web-based contrast tool by the experts at WebAIM. The tool allows you to plug in two different colors by their hex values, and it calculates the contrast between them, and if they meet or fail different WCAG color contrast standards. This tool also excels by offering a slider to lighten/darken your color inputs until it meets contrast requirements.

Colour Contrast Analyzer: The Paciello Group provides this desktop software to test color contrast, and it includes an eyedropper tool so you can select colors without needing to identify their hex values first. This software must be installed on your computer with the assistance of the IT department. provides a page filter that allows a user to input a specific url to see a version of the page that mimics what a person with colorblindness would see. The tool provides four different filters, each representing one of the forms of colorblindness. 

Screen Readers

You do not need to install, configure, or learn how to use a screen reader to do informal accessibility evaluations. Screen readers have a steep learning curve to use proficiently, and some native screen reader-users opine that sighted users should not attempt to make changes to their website based on their experiences as novice screen reader-users. This is a purely optional tool if you are interested in experiencing how screen readers help people navigate their computers. 

Optional Screen Readers

Voiceover: This software is built into all Mac computers. It is the de facto standard for screen reader users who use macOS.

JAWS: This is the standard for Windows readers. It’s powerful, highly customizable, but also complex and expensive. Unless you already have a license to use JAWS and are familiar with it, this is not recommended for a lay person tester.

NVDA: An open-source alternative to JAWS. NVDA is growing in popularity, especially amongst younger users. It doesn’t have quite as many options as JAWS, which along with it’s price (free) makes it a good choice for those interested in a Windows-based reader.

ChromeVox: This is a Chrome extension that provides a basic screen reader for the Chrome browser only. Very few people who rely on screen readers use ChromeVox, but if you just want to get a feel for how screen readers operate without investing a lot of time into it, it’s suitable for a demo of the technology.

Screen Magnifiers

Some people with limited vision use screen magnifiers, software that acts like a magnifying glass, enlarging the content wherever the cursor is pointing, up to 20x size. Some screen magnification software also reads out the content that has visual focus.

ZoomText – This is the most popular screen magnification software. It is made by the same company that produces JAWS, and like JAWS, is licensed commercial software. Also like JAWS, this is only recommended if you already have a license for it and are interested.

Built-in Zoom – You can zoom into most computer programs, albeit at a lower level, using standard keystrokes and without any special software. Hold control and hit “+” and “-” on your keyboard to zoom in and out, or hold control and use the scroll wheel on the mouse. You should be able to zoom into the content up to 200% without any loss of functionality. Many websites switch to a mobile layout at this level of zoom, which is acceptable.

Reading Level Checkers

Automatic Readability Checkers take a writing sample as input and calculate the number of sentences, words, syllables and characters in the text. They then use one or more readability formulas to calculate the reading and grade level of the text to help determine if your audience can read the content. 

Recommended Reading Level Checkers

Readability Formulas uses seven of the most popular formulas to provide an aggregate grade level, reading level and reader’s age score.

Canvas Tools

The EOU Canvas installation includes an external tool called Ally that provides a wide range of accessibility data, reporting, and tips to improve course content. The ally tool is located on the left sidebar of the admin pane within Canvas. Instructors can find documentation and resources at the Ally website.