Testing web accessibility: manual, automated and assistive technologies

Sergey Lebedev
5 min readAug 2, 2023


Welcome to the third and final installment of our comprehensive web accessibility series. In our previous articles, we explored the key principles of web accessibility, delved into a11y design patterns, and discussed the importance of accessibility validation. Now, it’s time to embark on an exciting journey into the world of testing web accessibility.

Testing web accessibility is a crucial step in the development process to ensure that your digital content is accessible to all users, regardless of their abilities. By testing your web applications and websites, you can identify potential barriers faced by users with disabilities and make necessary improvements to create a more inclusive web.

In this article, we will explore various testing methodologies, ranging from manual and semi-manual techniques to automated tools and assistive technologies. We’ll equip you with the knowledge and resources to conduct comprehensive accessibility testing, enabling you to provide a seamless and inclusive experience for all users.

Let’s dive into the world of testing web accessibility and make the internet a more inclusive place for everyone!

Why test web accessibility?

Before we delve into the testing techniques, let’s understand why testing web accessibility is a critical aspect of web development. Accessibility testing ensures that your web content can be accessed, understood, and interacted with by all individuals, regardless of their abilities. By testing for accessibility, you demonstrate a commitment to inclusivity and compliance with accessibility standards such as the Web Content Accessibility Guidelines (WCAG).

It’s essential to remember that web accessibility is not a one-time task but an ongoing process. As technology evolves, so do the needs and challenges faced by users with disabilities. Regular testing and evaluation allow you to identify and address accessibility issues, ensuring that your website remains accessible to all users, both now and in the future.

Manual and semi-manual testing

  1. Keyboard navigation: One of the fundamental aspects of manual accessibility testing is ensuring proper keyboard navigation. Test all interactive elements, such as links, buttons, and form fields, using only the keyboard. Ensure that users can navigate through the content and interact with all elements easily.
  2. Screen reader testing: To understand how users with visual impairments experience your web content, use a screen reader. Familiarize yourself with popular screen readers like VoiceOver (macOS) and NVDA (Windows) to navigate your website effectively and identify any issues with the reading order and information conveyed through ARIA attributes.
  3. Color contrast evaluation: Manually evaluate the color contrast of your web page elements using online color contrast tools or browser extensions. Ensure that text and other important elements meet the minimum contrast requirements specified in the WCAG.
  4. Form accessibility: Test form fields for proper labeling, error handling, and accessibility attributes like “autocomplete.” Verify that users can complete and submit forms using assistive technologies.
  5. Semantic structure: Review the HTML structure of your web pages to ensure the proper use of headings, lists, and landmarks. Proper semantic structure enhances navigation for all users and helps assistive technologies understand the content better.

Automated Testing

Automated testing tools significantly streamline the accessibility testing process, providing rapid feedback on potential issues. However, it’s essential to understand that automated tools cannot catch all accessibility concerns, and manual testing remains a vital component of a comprehensive accessibility testing strategy.

  1. axe-core: As a JavaScript library, axe-core offers automated accessibility testing for web applications. By integrating axe-core into your development workflow, you can identify and resolve accessibility issues early in the development process.
  2. Pa11y: Pa11y is another popular automated accessibility testing tool that allows you to run tests against multiple pages and provide detailed reports on accessibility violations.
  3. Angular ESLint Rules for A11y: If you’re using Angular, consider using ESLint rules for accessibility to ensure your code follows best practices and meets accessibility standards.

Automated testing is particularly useful for catching common accessibility issues, such as missing alt attributes, improper heading structure, and form validation errors. These tools can scan large websites efficiently, making them valuable for assessing overall accessibility compliance.

Assistive technologies

Assistive technologies play a vital role in web accessibility testing. These tools simulate the experiences of users with disabilities, helping developers understand potential challenges faced by this audience.

  1. Screen Reader (Chrome Extension): Chrome offers an extension that simulates a screen reader, allowing you to experience your web content through the eyes of users with visual impairments. This tool is valuable for understanding how screen readers interpret and navigate your website.
  2. VoiceOver on Mac and NVDA on Windows: VoiceOver is a screen reader built into macOS, while NVDA is a popular screen reader for Windows. Familiarize yourself with these assistive technologies to gain insights into how users with visual impairments access your web content.
  3. Accessibility Insights for Web (Chrome Extension): This Chrome extension by Microsoft helps developers find and fix accessibility issues during development. It offers a comprehensive set of tools, including automated tests and a full accessibility tree.
  4. WCAG Color Contrast Checker (Chrome Extension): This extension allows you to test the color contrast of your web page elements, ensuring they meet WCAG’s minimum contrast ratio requirements.
  5. Live Region Playground: The Live Region Playground by Deque University is an interactive tool for testing ARIA live regions and ensuring that they behave as expected for users with screen readers.
  6. WAVE Web Accessibility Evaluation Tool: WAVE is a web accessibility evaluation tool that provides visual feedback about the accessibility of your web content. It highlights potential issues and offers suggestions for improvement.
  7. The ARIA Authoring Practices Guide (APG): The APG provides guidance on using WAI-ARIA roles, states, and properties to make web content more accessible to users with disabilities.

Congratulations on completing our web accessibility series! By understanding the key principles, exploring A11y design patterns, mastering accessibility validation, and learning about testing methodologies, you’ve gained valuable insights into creating a more inclusive digital experience.

Remember, accessibility is a journey, and it’s essential to keep refining your skills and knowledge. By integrating accessibility best practices into your development process, you contribute to a web that is accessible and welcoming to all users.

We hope that the knowledge gained from this series empowers you to create more inclusive web content, breaking barriers and making the internet accessible to everyone, regardless of their abilities.

In the spirit of continuous learning, let’s explore other aspects of web accessibility and stay committed to building a web that truly leaves no one behind. Consider reading more about accessible design, inclusive development practices, and assistive technologies to further deepen your expertise in web accessibility.

Together, we can shape a digital world where diversity is celebrated, and everyone can participate fully. Let’s continue making the internet a place that fosters equality, inclusivity, and equal access for all users. Happy accessible coding!

Additional resources

  1. Chrome devtools Accessibility tab: Chrome’s Accessibility tab for inspecting accessibility tree.
  2. Lighthouse: Google’s automated tool for auditing web accessibility.
  3. A11ycasts with Rob Dodson: Video series on web accessibility by Rob Dodson.
  4. Web Accessibility — Udacity course: Udacity’s course on web accessibility.



Sergey Lebedev

Senior Frontend Developer • Team Lead • JavaScript, Angular, React, TypeScript • UI/UX