Accessibility test: How to check your website properly

How can I check my website's accessibility?

Digital accessibility is much more than a technical implementation; it's a social necessity and a legal obligation.

Globally, an estimated 1.3 billion people live with a significant disability. For them—as well as for older individuals or people using a site under specific conditions (e.g., strong sunlight or mobile use)—accessibility determines whether they can use digital content at all.

This is compounded by pressure from statutory requirements. The recent European Accessibility Act (EAA) place a legal duty on companies to ensure the digital accessibility of their products and web applications. Failure to act not only risks legal repercussions but also potentially excludes millions of users.

The good news is that inclusion and commercial success go hand-in-hand. An accessible website offers:

• Wider reach: You tap into more potential customers.

• Better SEO visibility: Many accessibility criteria (such as clear structure and meaningful alternative text) also boost your search engine ranking.

• Improved usability: A clear, structured design benefits all users.

To meet and maintain this standard at a high level, a systematic accessibility test is essential. Various interconnected methods are available for this purpose.

Overview of accessibility tests

Automated tests

Automated accessibility tests are the fastest and most cost-effective way to get a preliminary picture of the state of your website or web application.

Even the developer tools built into common browsers can, with a few clicks, provide valuable pointers and uncover about 30 to 50 per cent of typical technical glitches—such as missing alternative text, insufficient colour contrast, or faulty HTML code.

Those needing a deeper analysis rely on specialised testing software. This software can automatically crawl not just individual pages but entire websites and generate detailed reports in a short time. This allows you to quickly pinpoint initial weak spots and set up a continuous testing process.

However, automated methods have clear limitations. They work a bit like a spellchecker: typos are spotted, but whether a text is clearly written or a navigation is logically structured remains unevaluated.

The quality of alternative text also can't be reliably assessed by a machine. For a truly comprehensive picture of the user experience, supplementary manual tests are absolutely indispensable.

Manual Tests

To capture aspects that automated methods miss, manual tests are crucial. The focus here is on genuine operability: Can the entire website be used alternatively with just the keyboard? Are headings clearly structured, forms correctly labelled, and navigation elements logically built?

A central element is testing with screen readers such as NVDA, JAWS, or VoiceOver. Only then does it become clear whether ARIA attributes have been correctly implemented and the source code is semantically sound. Furthermore, cognitive accessibility plays a role: Are error messages clearly phrased, is the menu navigation logical, and is the content not overwhelming?

Alongside using plain English, UX methods such as user journeys or accessibility heuristics can help systematically review the user experience from different viewpoints.

Checking mobile usability is also vital. Responsive design, sufficiently large click targets, and operability at up to 200% zoom are mandatory. The linguistic style also contributes to accessibility: Readability analyses with simple tools help to simplify texts and make content more broadly understandable.

Guided checks & hybrid approaches

Between the quick but limited automated methods and expert audits, there are hybrid approaches that combine both. Semi-automated guided testing systems lead teams through the most important inspection steps with clear workflows and checklists, documenting the results directly in the software. This allows less experienced staff to test in a structured manner and spot typical barriers early on.

User testing with people with disabilities is also particularly valuable. This "Crowdsourced Testing" provides practical feedback and shows whether an application truly works in day-to-day life. Ultimately, the best accessibility test is the one that measures the actual experience of users.

Expert-based accessibility audits

For compliance with statutory requirements, such as those demanded by the EAA, expert audits are the most reliable path. Specialists check your website or web application against official criteria catalogues like the Web Content Accessibility Guidelines (WCAG) or related national standards. The analysis is usually based on a representative sample, which is evaluated in detail and provides a precise picture of the level of accessibility.

A successful audit can lead to an accessibility mark or certification. This not only creates legal certainty but also strengthens user trust. Since websites and applications are continuously being developed, it is advisable to repeat such audits regularly—ideally annually.

Assistive tools

Assistive tools can make a website easier to use by enabling individual adjustments—such as enlarged text, altered contrast, or read-aloud functions. They thus offer real added value for specific user groups.

However, these solutions quickly reach their limits. So-called overlay technologies are often promoted as a quick "all-in-one" fix but cannot resolve fundamental barriers. Structural errors in the HTML code, missing alternative text, or illogical navigation persist. Such tools are therefore merely a temporary supplement and should never replace a cleanly developed website that is accessible by design.

The progressive testing approach

Accessibility isn't a one-off project; it’s an ongoing process. An efficient approach therefore means: testing regularly, combining different methods, and integrating results into further development step-by-step.

View accessibility as continuous development

Accessibility isn't an "on/off switch," but a gradual process. The goal is to move closer to the WCAG criteria step-by-step—and in doing so, not only meet statutory requirements but also permanently boost user-friendliness.

Combine methods intelligently

An effective testing process links different levels:

• Weekly/Daily: Automated tests for new or changed pages.

• Monthly: Targeted manual checks of key pages, e.g., keyboard navigation or forms.

• Annually: Comprehensive expert audits, such as WCAG tests.

This creates a balanced system that ensures both rapid responsiveness and long-term quality assurance.

Embed accessibility in workflows

For this approach to work, accessibility must be firmly integrated into the development process. This includes clear responsibilities within the team and integrating tests as a fixed component of the CI/CD workflow (Continuous Integration/Continuous Delivery). Only this way does accessibility become a matter of course in the digital everyday.

Conclusion

Accessibility is not a one-time project, but an ongoing process. With a clear testing approach—from automated teststo manual tests and expert audits—you lay a solid foundation for an inclusive website. The crucial thing is to continuously integrate accessibility into your working procedures and regularly check it.

This benefits not only people with disabilities but all your users through better operability, more understandable content, and an overall more pleasant user experience. Those who invest today gain long-term reach, trust, and legal security.

FAQs

Which testing method should I apply first?

The best way to start is with an automated test. Use a free website scan, for example, to quickly identify the most obvious accessibility issues and implement initial improvements. Manual tests should follow in the next step—such as checking keyboard operability—to fully map the user experience.

How often should I conduct accessibility tests?

Automated tests should run with every major change or at least weekly. Manual tests should be carried out monthly on key areas, and a comprehensive expert audit (WCAG test) is advisable annually or with major relaunches.

Can assistive tools replace accessible coding?

No. Assistive tools and overlay technologies are an individual supplement, but not a substitute for accessible coding of your web application. Fundamental structural errors in the HTML code must be fixed in the source code.

What is the cost of professional accessibility tests?

The costs vary widely. Automated tests are often free or low-cost. The cost for a detailed expert audit (WCAG test) is determined by the scope and complexity of the web application to be checked.