What Is Web Accessibility Testing – Ultimate Guide

The internet is meant to be for everyone, but many websites still create barriers (unintentionally) for people with disabilities. Web accessibility testing helps identify these barriers, which must be removed so everyone can access and use a site.

In this guide, we’ll explain what web accessibility testing is, the different approaches you can take, and the tools that can help. By the end, you’ll know how to test your own website or app for accessibility and make it more inclusive for every visitor.

What Is Web Accessibility Testing?

Web accessibility testing is the process of checking whether a website or web-based application can be used by people with disabilities. It ensures that users with visual, auditory, motor, or cognitive impairments can access and interact with your site without barriers.

In practice, web accessibility testing involves evaluating a site or application against the Web Content Accessibility Guidelines (WCAG). In case you’re unfamiliar, WCAG is the standard used worldwide for making online experiences accessible to people with disabilities.

It is important to remember that accessibility testing is not a one-time activity. As websites and apps evolve, new barriers can appear. You should test after major updates and aim for a full review every quarter, or at least once every six months, to keep your site inclusive.

Web Accessibility Testing Approaches

Testing web accessibility requires more than one approach, since no single method can uncover every issue. Each approach identifies different types of barriers, and when combined, they provide a more accurate picture of how accessible your site truly is.

The main approaches are:

• Automated testing
• Manual testing
• User testing with people with disabilities

In most cases, a mix of automated and manual testing will uncover the majority of issues. However, user testing adds valuable depth and real-world insights, though it can be treated as optional if budgets or resources are limited.

1. Automated testing

Automated tools, such as WebYes, scan web pages to detect common accessibility issues. They can quickly identify missing alt text, poor colour contrast, or incorrect heading structures. While they are fast and helpful, they typically catch only a fraction of accessibility issues.

2. Manual testing

Manual checks involve human testers actively interacting with the site to spot accessibility barriers. By navigating with only a keyboard, checking link clarity, reviewing form labels, or using assistive technologies, they can uncover usability barriers that automated tools miss.

3. User testing with people with disabilities

User testing helps uncover barriers that automated tools and manual checks might miss. It brings authentic insights that professional testers alone cannot provide. Involving even a small group of users with disabilities can add meaningful depth and reliability to your testing.

How to Do Web Accessibility Testing

To do web accessibility testing effectively, it helps to follow a structured process. Breaking the process into smaller steps makes it easier to manage, ensures consistency, and reduces the chance of missing important checks.

We’ve outlined six key steps to guide you through accessibility testing:

1. Set the WCAG version and conformance level to test against.
2. Define the scope to decide what parts of the site or app to test.
3. Run automated scans to quickly catch common accessibility issues.
4. Perform manual checks to uncover barriers automation might miss.
5. Involve users with disabilities to get authentic, real-world feedback.
6. Document findings to track issues, assign responsibility, and set priorities.

Now, let’s go through each step in detail.

1. Set the WCAG version and conformance level

Decide the level of accessibility you are aiming for.

The Web Content Accessibility Guidelines (WCAG) currently exist in three versions: 2.0, 2.1, and 2.2. Each version builds on the one before it, introducing additional requirements to reflect changes in technology, the way people use devices, and the accessibility needs of users.

WCAG also defines three conformance levels:

• Level A: the most basic requirements for accessibility.
• Level AA: the recommended level for most websites, balancing usability and feasibility.
• Level AAA: the highest standard, covering advanced accessibility needs, but often not realistic for all content.

By selecting the version and conformance level you’re aiming for, you create a clear benchmark for accessibility testing.

2. Define the scope

Decide which parts of your site or app you will test.

This could be the entire site, a set of key pages, or critical features like checkout or forms. Ideally, every page should be accessible, but testing the whole site can be time-consuming and costly, especially when done manually. Focus first on the user journeys that matter most.

In WebYes, you get the option to select priority URLs when performing a scan, which helps you focus on your most important pages first. This makes prioritisation easier, especially for high-traffic or conversion-critical areas like the homepage, checkout, or sign-up flows.

3. Run automated scans

Begin the web accessibility testing with automated tools.

Automated testing tools, such as WebYes, can quickly detect common issues like missing alt text, poor colour contrast, or incorrect heading order. Their speed makes them an efficient starting point, helping you identify issues across multiple pages in a short time.

4. Perform manual checks

Look for issues that automation can’t catch.

For example, an automated tool can confirm that a form displays an error message, but it cannot judge whether that message is meaningful or easy to understand. Similarly, a tool might detect that a button has a label, but only a human tester can assess if the label makes sense in context.

Manual testing helps uncover these contextual issues by interacting with the site as a user would. This includes navigating with only a keyboard, reviewing forms and error messages, and using assistive technologies like screen readers to check how content is announced.

5. Involve users with disabilities

Bring real users into the testing process.

People with disabilities can provide authentic feedback based on real experiences, often uncovering issues that tools or professional testers might miss. So, if possible, involve a small group of users to make your testing more accurate and user-centred.

6. Document findings

Record the issues you uncover during testing for future review and fixes.

Note what the issues are, where they occur, who is responsible for fixing them, and how severe the impact is to set priority. This helps track progress, assign clear ownership, and ensure the most critical issues are resolved first.

Web Accessibility Testing Tools

Web accessibility testing requires a mix of tools, since no single tool can cover everything. Different tools serve different purposes, from automated scans to assistive technologies.

The table below groups some of the most commonly used web accessibility tools by category.

Category	Purpose	Example
Automated Testing Tools	Quickly scan websites for common accessibility issues	WebYes, WAVE, axe DevTools, Lighthouse
Document Accessibility Checkers	Test PDFs and Office documents for accessibility compliance	Adobe Acrobat Pro, PAC 2025, Mauve++
Screen Readers	Assistive technology that reads content aloud for blind, low-vision, or some cognitive users (also useful for testing)	NVDA (Windows), VoiceOver (macOS/iOS), JAWS (Windows)
Colour Contrast Checkers	Test if text and background colours meet WCAG contrast ratio requirements	WebYes Colour Contrast Checker, Accessible Web Contrast Checker
On-page Testing Extensions	Run quick, in-browser accessibility checks while viewing a specific page	Silktide, Accessibility Insights

Automated testing tools

Accessibility testing can be time-consuming, especially on large websites. Automated testing tools help by quickly scanning pages and flagging common accessibility issues. They provide speed and coverage, making them an essential first step in any testing process.

WebYes is one such tool that can scan multiple pages and highlight common issues efficiently. While automated tools save time and provide useful insights, manual testing is still needed to catch the problems that automation misses and ensure a thorough review.

Document accessibility checkers

Accessibility doesn’t stop at web pages. The documents shared on your website, such as PDFs or Word files, should also be accessible. In fact, accessibility laws like the European Accessibility Act require all documents published online to meet accessibility standards.

Tools like Adobe Acrobat Pro, PAC 2025, and Mauve++ can check PDFs for issues such as missing tags, incorrect reading order, or inaccessible tables. For Word and other Office files, you can use the built-in accessibility checker available in the Microsoft suite.

Screen readers

Screen readers let you experience your site the way a blind or low-vision user would. They announce page content, link text, form fields, and error messages, giving you insight into whether your site is understandable and navigable for users who rely on assistive technology.

Therefore, testing how screen readers announce content is an essential part of web accessibility testing, as unclear or missing announcements can create major barriers. So, aim to test with NVDA and VoiceOver, or at least one of them.

Colour contrast checkers

Colour contrast is one of the most common accessibility issues. Poor contrast between text and background can make content unreadable for people with low vision or colour blindness. Contrast checkers help you measure ratios against WCAG requirements to ensure readability.

Popular tools like WebYes Colour Contrast Checker let you quickly test text and background combinations. They’re simple but powerful, especially for designers who need to confirm that their choices meet accessibility standards before implementation.

On-page testing extensions

Sometimes you need quick, page-level checks without running a full site scan. On-page accessibility extensions make this possible directly in the browser. They let you run instant tests on whatever page you’re viewing, giving developers and testers fast feedback during design or development.

Extensions like Accessibility Insights for Web and the Silktide browser extension can highlight issues in real time. They’re especially useful for spotting problems early, but like other automated tools, they should be paired with manual checks for a complete picture.

What to Do After Accessibility Testing

Testing highlights the issues, but the real impact comes from what you do next. Once your findings are documented, the next step is to fix problems, validate the fixes, and make accessibility a continuous part of your workflow.

1. Prioritise issues

Not every issue carries the same weight. Start by addressing critical issues that block users from completing key actions, such as filling out forms, using navigation, or accessing content. Tackle high-severity problems first, then move to moderate and minor ones.

2. Assign responsibility

Accessibility fixes often span different teams. Developers handle code-related issues, designers refine visual and interaction elements, and content creators improve text or alt descriptions. Assign each issue to the right person or team to ensure accountability.

3. Fix and verify

Once changes are made, run another round of testing. Use automated tools for a quick check and follow up with manual testing to ensure problems are fully resolved. If possible, bring in users with disabilities again to validate improvements.

4. Keep records

Maintain a log of all fixes along with the steps taken to verify them. This provides an audit trail for compliance purposes and helps you track progress over time. It also makes it easier to identify recurring issues that may need deeper attention.

5. Make it ongoing

Accessibility isn’t something you check off once and forget. New issues can appear as you add content, update designs, or release new features. Therefore, build accessibility checks into development, publishing, and QA, so problems are caught early.

How to Integrate Web Accessibility Testing Into Your Workflow

So far, we have been talking about testing after a site or app is built.

While that’s important, web accessibility testing is most effective when it’s part of the entire workflow rather than a final step. By shifting accessibility to the left, you bring testing into earlier stages of the process and catch issues before they become harder and more expensive to fix.

In practice, accessibility checks should be built into key stages of the workflow, as shown below:

Stage	What to Test	Who’s Responsible
Design	Review colour contrast, font readability, and visible focus indicators.	Designers
Development	Check code against accessibility standards and fix issues before release.	Developers
QA & Pre-launch	Validate accessibility with manual checks, assistive technologies, and user testing where possible.	Testers / QA Teams
Post-launch	Run regular audits to catch new issues from updates, new content, or design changes.	Shared across teams

By assigning responsibilities at each stage, accessibility testing becomes a shared effort rather than a last-minute task. Designers, developers, and testers all play a role in catching different types of issues, which ensures broader coverage and fewer barriers slipping through.

This integrated approach makes accessibility a natural part of the workflow instead of an afterthought.

Wrapping Up

Web accessibility testing is a necessary step in making websites and apps usable for everyone. By weaving it into the workflow and involving designers, developers, and testers at the right stages, you can catch barriers early and maintain accessibility as your site evolves.

Don’t wait until problems become too big to ignore. Test regularly, make accessibility part of your ongoing process, and address issues as they arise to keep barriers from piling up. In doing so, you’ll build digital experiences that truly work for everyone.