External Tools and Resources

When testing with assistive technologies, online checkers, plugins, and other tools we must stress: no two are alike. Developers and content creators are cautioned to use these tools as an approximate gauge of accessibility.

Developers and content creators should not solely focus on using one product or testing tool, but should instead rely on understanding and following standards and then testing with a variety of tools. Ultimately, testing technology with a variety of screen readers is the best assessment of its accessibility. 

Many external tools and resources exist to help you create of accessible technologies. If you have any additions or modifications to this list, please contact the accessible technology coordinator.


Web and Document Accessibility Training and Education

These organizations and vendors are at the forefront for educating on digital accessibility guidelines, best practices, and testing.

  • WebAIM (Web Accessibility In Mind): With the mission to empower organizations to make their web content accessible to those with disabilities, this site includes introductory tutorials, articles for audiences of all expertise levels, a blog, an active discussion list, and more.
  • W3C: The web accessibility initiative (WAI) aims to create standards to assist web developers in creating websites and web applications free of barriers to individuals with disabilities.
  • Level Access: An up to date resource for news and trends, a creator of accessibility checking software, and training and documentation service provider. More than half of their staff has some form of disability, ensuring that recommendations and resources solve problems that make a difference.
  • A List Apart: Explores the design, development, and meaning of web content, with a special focus on web standards and best practices. The proper application of many design and development principles also ensure an accessible web.
  • Adobe Accessibility: Tutorials, best practices and white papers about accessibility of Adobe products. Adobe's products affect a number of source documents that lead to content on the web.  Adobe also offers the Acrobat Accessibility Series on PDF accessibility and remediation strategies.

Guidelines and Standards

It is import to understand and implement proper standards related to both web development and accessibility standards. Useful resources include: 

  • HTML5 Standards: Helps developers ensure that basic HTML content is compatible with assistive technology.
  • Web Content Accessibility Guidelines 2.0 (WCAG): The definitive set of web accessibility guidelines, from the World Wide Web Consortium (W3C). WCAG 2.0 covers a wide range of recommendations for making content more accessible. 
  • Accessible Rich Internet Applications (ARIA): A W3C specification that defines a way to make content and web applications more accessible. It helps with dynamic content and advanced user interface controls developed with Ajax, HTML, Javascript, and related technologies.

HTML / Markup Validators

Having valid code is a first step toward web accessibility and cross-browser and screen reader compatibility.

  • Total Validator: Validates HTML and CSS, checks that pages are accessible, runs a spell check, and checks for broken links—performing a one-click validation of your website.
  • W3C Markup Validation Service: Checks the markup validity of Web documents in HTML, XHTML, SMIL, MathML, etc.

Accessibility Validators

These online tools can assist in validating your web content for accessibility.

  • Functional Accessibility Evaluator (FAE): Online web accessibility evaluator from the University of Illinois, designed for testing WCAG 2.0 Level A and AA requirements. FAE is capable of crawling a website and providing a summary report, plus reports for each individual page.
  • WAVE Web Accessibility Evaluation Tool: Developed by the folks at WebAIM, this online tool evaluates the accessibility of a webpage and shows results using icons and indicators, embedded onto the original page.

Color Contrast Checkers

The W3C’s Web Content Accessibility Guidelines 2.0 requires a specific contrast ratio between foreground and background colors. There are several tools available for measuring contrast:

  • WebAIM Color Contrast Checker: This online tool calculates the contrast between two input colors and includes a feature to incrementally "lighten" or "darken" them until you find a combination that meets WCAG 2.0 requirements.
  • Colour Contrast Analyser: This free application for Mac and Windows is developed and maintained by the Paciello Group.  It provides a pass/fail assessment of color contrast and offers a simulation of visual conditions such as dichromatic color-blindness.
  • Luminosity Colour Contrast Ratio Analyser: This free application makes it easy to check foreground and background color combinations for contrast. Included is an eyedropper tool for easily grabbing a particular color from anywhere on screen.


Web developers can add these toolbars to their tool collection to assist in ensuring their websites and web applications are accessible.

  • Web Developer Toolbar for Firefox or Chrome: This highly useful toolbar is packed with features, including many that help developers create websites that are accessible.
  • WAVE Chrome Extension: This toolbar from WebAIM includes a few different accessibility rules and user interface options separate from their online tool.

Assistive Technologies: Screen Readers

Screen readers allow the individuals with visual impairments to easily access electronic information. These software programs connect to a computer to read the text displayed in a website or web application out loud.

  • JAWS: "Job Access With Speech" is a computer screen reader program for Microsoft Windows that allows individuals with no sight or visual impairments to read a screen either with a text-to-speech output or by a refreshable Braille display. JAWS + Internet Explorer (IE) is the most common web browser combination that screen reader users have.
  • NVDA: "Non-Visual Desktop Access” is a free, open source screen reader program for Microsoft Windows, most often paired with FireFox. WebAIM publishes a handy guide on Using NVDA to Evaluate Web Accessibility.
  • VoiceOver: The default screen reader program built into Mac OS X, as well as iOS devices such as the iPhone and iPad. VoiceOver is mostly commonly used wit the Safari web browser. WebAIM publishes a handy guide on Using VoiceOver to Evaluate Web Accessibility.
  • ChromeVox: ChromeVox is Google’s default screen reader built into Chrome OS. It is also available as an extension for the Google Chrome web browser and is most commonly used with the Chrome web browser.