A Complete Guide to WCAG Testing: What Should You Check First?

If you want to test your website against WCAG requirements, the hardest part is often knowing where to begin. WCAG includes dozens of success criteria, and testing everything at once usually leads to scattered results and unclear priorities.

The surprising thing is that many teams still start WCAG testing by running long automated reports or generic checklists. This often produces a lot of data but very little clarity about what actually blocks users.

With the right testing order, you can identify critical accessibility issues early, reduce legal and usability risk, and make WCAG testing far more manageable. Let’s walk through what to check first and why it matters.

What Is WCAG Testing?

WCAG testing is the process of evaluating whether a website meets the Web Content Accessibility Guidelines. These guidelines are built around four core principles: content must be perceivable, operable, understandable, and robust.

WCAG includes three conformance levels. Level A addresses basic accessibility barriers, Level AA is the standard most regulations require, and Level AAA goes beyond typical compliance expectations. In practice, most WCAG testing efforts should focus on Level A and Level AA first.

Why Knowing What to Test First Matters

Not all accessibility issues have the same impact. Some problems create minor friction, while others completely prevent users from accessing content or completing tasks.

When teams test without prioritization, they often spend time fixing low impact issues while leaving critical blockers unresolved. A better approach is to focus on issues that affect core user actions such as navigation, reading, and form submission.

Testing in the right order leads to faster improvements and more meaningful accessibility outcomes.

Start With Perceivable Issues First

Perceivable issues determine whether users can access your content at all. If text cannot be read or media cannot be understood, nothing else on the page matters.

The first round of WCAG testing should focus on:

Text alternatives for images and icons
Sufficient color contrast for readable content
Captions or transcripts for video and audio

These issues affect users with visual and hearing impairments and are among the most common WCAG failures.

Test Keyboard Accessibility Early

Keyboard accessibility is one of the most critical areas of WCAG testing and one of the easiest to validate manually.

Users should be able to navigate the entire website using only a keyboard. Focus indicators must be visible, and the navigation order should follow the visual structure of the page. Special attention should be given to menus, modals, and dynamic components, where keyboard traps often appear.

If a user cannot move through the site with a keyboard, the experience is effectively broken.

Check Forms and Interactive Elements

Forms and interactive elements are frequent sources of accessibility problems. Even small mistakes can prevent users from completing important actions.

WCAG testing should confirm that form fields are clearly labeled, instructions are easy to understand, and error messages are communicated in a way assistive technologies can detect. Buttons and interactive controls should behave consistently and be accessible without a mouse.

Because forms are closely tied to conversions and communication, accessibility issues here carry both usability and compliance risk.

Validate Page Structure and Semantics

Proper page structure helps assistive technologies interpret content correctly. Screen readers rely on headings, landmarks, and semantic elements to navigate efficiently.

Testing should verify that headings follow a logical hierarchy, page regions are clearly defined, and links describe their destination. Strong structure improves accessibility and also supports search engines in understanding your content.

Don’t Skip Mobile WCAG Testing

WCAG testing should always include mobile devices. Touch interaction, screen size, and mobile assistive technologies introduce accessibility challenges that may not appear on desktop.

Mobile testing should consider zoom behavior, touch target spacing, and how content behaves when viewed with a mobile screen reader. Since many users rely primarily on mobile devices, skipping this step often leads to missed issues.

Automated vs Manual WCAG Testing

Automated testing is a helpful starting point, but it cannot fully evaluate accessibility on its own.

Automated tools are effective at identifying common issues such as missing alt text, contrast problems, and basic structural errors. Manual testing is required to assess keyboard behavior, screen reader experience, and overall usability.

Many teams begin by scanning key pages to understand recurring issues, then follow up with deeper manual evaluation. For example, reviewing early results from a tool like the Tabnav web checker can help highlight patterns before moving into hands-on testing.

What to Fix First After Testing

Once testing is complete, prioritization becomes critical.

Focus first on issues that:

Block navigation or form submission
Affect essential pages such as home, checkout, or contact
Map directly to WCAG Level A or AA success criteria

Fixing high impact issues first reduces risk and delivers faster improvements for users.

Next Steps After Your First WCAG Test

WCAG testing is not a one time task. Websites evolve, content changes, and new accessibility issues can appear over time.

After your initial test, establish a process for ongoing monitoring, retesting after updates, and documenting fixes. A consistent testing workflow makes accessibility sustainable instead of overwhelming.

Starting with the right checks sets the foundation for long term WCAG compliance and better user experiences.