How can I properly use website ac­cess­ib­il­ity checkers?

There are several ways to test your website’s ac­cess­ib­il­ity, including using website ac­cess­ib­il­ity checkers. Depending on your goals, site com­plex­ity, and desired technical depth, different tools and methods can help identify, assess, and fix common ac­cess­ib­il­ity issues.

How can I check if my website is ac­cess­ible?

There are multiple ways to check a website’s ac­cess­ib­il­ity. Ideally, you’ll make use of a com­bin­a­tion of automated tools and manual testing methods.

To start with, you can use browser plugins or online website ac­cess­ib­il­ity checkers to detect obvious issues. A common first step here is testing for colour contrast, al­tern­at­ive text for images, or checking the semantic HTML structure and form ac­cess­ib­il­ity, using the <label> tag. However, many ac­cess­ib­il­ity barriers go un­detec­ted by tools, such as unclear nav­ig­a­tion or confusing language.

Manual testing helps fill this gap by having real users or ac­cess­ib­il­ity experts using assistive tech­no­lo­gies test the website. The results of all tests should be doc­u­mented and pri­or­it­ised in order to implement gradual im­prove­ments going forward.

What is the legal framework for ac­cess­ib­il­ity in the UK?

In the United Kingdom, ac­cess­ib­il­ity for digital content is governed primarily by:

• The Equality Act 2010, which applies to busi­nesses, public services, and other or­gan­isa­tions. The act mandates that websites must be ac­cess­ible to people with dis­ab­il­it­ies, ensuring equal access to digital services.
• The Public Sector Bodies Ac­cess­ib­il­ity Reg­u­la­tions 2018, which applies to public sector or­gan­isa­tions, requiring them to make their websites and apps ac­cess­ible to people with dis­ab­il­it­ies.

Ad­di­tion­ally, the Web Content Ac­cess­ib­il­ity Guidelines (WCAG) 2.1 serve as the de facto technical standard for achieving ac­cess­ib­il­ity com­pli­ance, even though they are not directly codified into law for private busi­nesses. Non-com­pli­ance can lead to legal chal­lenges or in­vest­ig­a­tions by the Equality and Human Rights Com­mis­sion (EHRC), es­pe­cially if a website creates barriers for users with dis­ab­il­it­ies.

Ac­cess­ib­il­ity testing basics using automated vs manual tests

Before a website can be con­sidered ac­cess­ible, it needs to be tested across different usage scenarios. This requires both automated testing tools and manual testing - ideally used together. Each method has its own strengths and catches different types of ac­cess­ib­il­ity barriers.

Automated testing

Automated tests are quick efficient checks using software tools like website ac­cess­ib­il­ity checkers. They can detect issues like missing al­tern­at­ive text, poor colour contrast, or incorrect ARIA roles. These tools are par­tic­u­larly useful for initial ac­cess­ible web design as­sess­ments and for ongoing quality assurance. However, when testing ac­cess­ib­il­ity with these tools, you should keep in mind that they can only discover a certain per­cent­age of potential barriers. Key problems such as ambiguous language, in­ter­act­ive func­tion­al­ity flaws, or unclear nav­ig­a­tion struc­tures often go unnoticed.

Manual testing

Manual testing fills the gaps left by automated testing methods through targeted usability testing and expert analysis. These manual testing pro­ced­ures include operating the entire website using a keyboard, testing com­pat­ib­il­ity with screen readers, and assessing how clear and un­der­stand­able the language and content are. This process actively in­cor­por­ates the per­spect­ives and ex­per­i­ences of users with motor, sensory, or cognitive impair­ments. Only through this com­ple­ment­ary human eval­u­ation can many barriers that automated tools miss be iden­ti­fied.

If you want to determine whether your website is truly ac­cess­ible, im­ple­ment­ing a struc­tured testing process that combines both automated and manual methods is essential.

Top 5 website ac­cess­ib­il­ity checkers

For an initial overview of a website’s ac­cess­ib­il­ity, automated tools - also known as website ac­cess­ib­il­ity checkers - are par­tic­u­larly suitable. Below is a selection of different options.

WAVE (Web Ac­cess­ib­il­ity Eval­u­ation Tools)

WAVE is a practical and free browser tool that allows you to quickly evaluate the ac­cess­ib­il­ity of in­di­vidu­al web pages. It high­lights iden­ti­fied barriers directly within the page layout, im­me­di­ately showing where im­prove­ments are needed. Ad­di­tion­ally, WAVE offers specific guidance and re­com­mend­a­tions on how to fix the issues it finds. The tool is par­tic­u­larly well-suited for beginners who want to get a quick overview of their site’s ac­cess­ib­il­ity. In addition to the browser extension, WAVE also offers a paid API and a test engine that allows you to automate ac­cess­ib­il­ity testing and integrate them into de­vel­op­ment processes.

axe DevTools (by Deque Systems)

axe DevTools is a powerful, developer-focused browser plugin that provides a free, precise, and detailed analysis of website ac­cess­ib­il­ity. It detects a wide range of issues based on WCAG standards and provides specific guidance for fixing them, greatly sim­pli­fy­ing the work involved. The plugin is suitable for both de­velopers and QA teams looking to test ac­cess­ib­il­ity ef­fi­ciently. Deque Systems also offers ad­di­tion­al paid solutions to test website ac­cess­ib­il­ity. These enable seamless in­teg­ra­tion into common de­vel­op­ment en­vir­on­ments, IDEs, and CI/CD pipelines, allowing ac­cess­ib­il­ity testing to be automated as part of the de­vel­op­ment workflow.

Google Light­house

Google Light­house is an in­teg­rated testing tool in the Chrome browser, ac­cess­ible directly via the Developer Tools. Among other features, it provides an Ac­cess­ib­il­ity Score that gives a quick overview of a website’s ac­cess­ib­il­ity, along with specific sug­ges­tions for im­prove­ment. Light­house tests include colour contrast, semantic HTML struc­tures, and al­tern­at­ive texts for images. The tool also analyses other aspects such as per­form­ance, search engine op­tim­isa­tion (SEO), and best practices, making it par­tic­u­larly useful for com­pre­hens­ive website op­tim­isa­tion. Since it runs directly in the browser, no ad­di­tion­al in­stall­a­tion is needed, which makes getting started easier.

Siteim­prove Ac­cess­ib­il­ity Checker

Like the tools mentioned above, the Siteim­prove Ac­cess­ib­il­ity Checker is a free browser plugin that checks the ac­cess­ib­il­ity of web pages directly in the context of the current view. The tool visually high­lights detected issues and clas­si­fies them according to WCAG criteria, severity, and affected user groups. Par­tic­u­larly helpful is the clear ex­plan­a­tion of each issue and specific sug­ges­tions for fixes, making the tool ac­cess­ible even to non-de­velopers. Siteim­prove em­phas­ises practical relevance and user ori­ent­a­tion, making it ideal for content editors and users with limited technical knowledge. The tool can also be in­teg­rated into the paid Siteim­prove platform, allowing quality assurance, analytics and ac­cess­ib­il­ity to be managed centrally.

Ac­cess­ib­il­ity Insights

Ac­cess­ib­il­ity Insights is a free tool developed by Microsoft, available as a browser extension for Chrome and Edge. It supports both quick spot checks and in-depth ac­cess­ib­il­ity testing based on the WCAG guidelines. The tool offers two main functions: a FastPass for quick automated checks and an As­sess­ment mode that allows for step-by-step manual testing. Par­tic­u­larly helpful is the visual high­light­ing of barriers directly on the page, along with a struc­tured and well-doc­u­mented guide to fixing issues. Ac­cess­ib­il­ity Insights is spe­cific­ally aimed at de­velopers and is also available as a stan­dalone app for Windows.

Manual testing and ac­cess­ib­il­ity aids

Many problems that users encounter in everyday browsing can only be detected through manual testing. These include barriers related to content com­pre­hen­sion, structure, usability, or actual user ex­per­i­ence. The following methods and tools provide practical ways to test a website from different per­spect­ives.

Keyboard nav­ig­a­tion

One essential manual test is to operate the website entirely using only the keyboard. This involves checking whether all content and functions can be accessed and used without a mouse. Typically, the Tab key is used to move between elements, arrow keys for nav­ig­a­tion, and Enter or Spacebar to select items. This type of test is es­pe­cially important for users with motor impair­ments or those who rely on keyboard-based input devices.

Screen reader tests

Screen readers are programs that convert screen content into speech or Braille output for blind or visually impaired users. Testing with common tools like NVDA (Windows) or VoiceOver (macOS) simulates this usage scenario. These tests can reveal issues with semantic structure, such as heading hierarchy, reading order, or missing labels on in­ter­act­ive elements. Learning to use screen readers takes time but provides valuable insights into the actual usability of a website.

Zoom and contrast checks

Ac­cess­ib­il­ity isn’t at odds with modern web design trends - in fact, good design is ac­cess­ible by default. Testing at increased zoom levels (e.g., 200%) and sim­u­lat­ing colour vision de­fi­cien­cies (e.g., grayscale mode) can help reveal design flaws and barriers for users with visual impair­ments. Common issues include poor colour contrast, content getting cut off, or interface elements that don’t scale properly. Most operating systems and browsers already include built-in features for running these checks quickly and easily.

Clarity of content

Ac­cess­ib­il­ity is not just a technical issue. Website content must also be easy to un­der­stand. Text should be clearly struc­tured, readable, and prefer­ably written in plain language. Check whether technical terms are explained, sentences are concise, and para­graphs are logically organised. Ar­ti­fi­cial in­tel­li­gence and language models LLMs can help evaluate how un­der­stand­able your content is, or suggest simpler al­tern­at­ive wording. In­ter­act­ive elements, such as forms or tools for scanning QR codes on a PC should also be designed for ac­cess­ib­il­ity and tested ac­cord­ingly. This benefits not only people with cognitive dis­ab­il­it­ies but also users with limited reading pro­fi­ciency or non-native English speakers.

Check­lists and WCAG criteria

The WCAG 2.1 define four key prin­ciples of digital ac­cess­ib­il­ity: per­ceiv­ab­il­ity, op­er­ab­il­ity, un­der­stand­ab­il­ity, and ro­bust­ness - often ab­bre­vi­ated as POUR. These prin­ciples form the found­a­tion of many re­cog­nised testing pro­ced­ures and check­lists, such as the BITV test or the practical WCAG check­lists provided by or­gan­isa­tions like WAI or DIAS. Such struc­tured testing tools help sys­tem­at­ic­ally identify ac­cess­ib­il­ity barriers, pri­or­it­ise necessary actions, and document progress in a trans­par­ent and traceable way.

What happens after testing?

After testing, the next step is doc­u­ment­ing and analysing the results - ideally with clear priority ratings like ‘critical,’ ‘medium,’ or ‘low.’ Focus first on barriers that create major obstacles for users or have legal im­plic­a­tions, like missing al­tern­at­ive text for images. These problems should be your top priority.

Long-term success means building ac­cess­ib­il­ity prin­ciples into your design, de­vel­op­ment, and content creation processes. Think of ac­cess­ib­il­ity as an ongoing re­spons­ib­il­ity rather than a one-time project. Here con­tinu­ous im­prove­ment is key. It’s also a good idea to plan follow-up testing after major changes like website re­launches, technical updates, or new content additions to maintain the standards you’ve worked hard to achieve.

Con­clu­sion

Testing website ac­cess­ib­il­ity is not a one-time effort. It’s an ongoing process. By combining automated tools, manual testing methods, and well-struc­tured check­lists, you can identify and fix many ac­cess­ib­il­ity barriers early on, before they become major issues. Ac­cess­ib­il­ity goes beyond simply meeting legal re­quire­ments. Digital inclusion makes both ethical and business sense for today’s websites.