Accessibility Testing for Developers: What Automated Tools Miss

Automated accessibility tools are useful, but they only show part of the picture.
A scanner can identify missing labels, contrast problems, invalid ARIA, and other rule-based issues. What it cannot reliably tell you is whether the interface actually makes sense to someone using a keyboard, screen reader, or another assistive technology.

What Automated Checks Do Well

Tools such as axe, Lighthouse, WAVE, and Accessibility Insights are good for catching issues that can be detected programmatically.
They can quickly flag problems such as missing accessible names, incorrect ARIA attributes, some contrast failures, missing form labels, and structural issues.
This makes them useful during development and regression testing.

Where Automated Scanners Fall Short

Passing an automated scan does not mean the experience is accessible.
A tool may confirm that an image has alt text, but it cannot always judge whether that text is useful. It may see that a button can receive focus, but not whether the focus order makes sense across the full page.
A broader accessibility testing approach is needed to catch issues that depend on context and real user interaction.

Keyboard Testing Still Matters

Developers should test important workflows without using a mouse.
Focus should move in a logical order, remain visible, and reach every interactive control. Menus, modals, dropdowns, and custom components should also work without trapping the user.
Keyboard testing is one of the fastest ways to expose problems that automated tools may miss.

ARIA Needs Human Review

ARIA can improve accessibility when used correctly, but incorrect ARIA can make an interface more confusing.
Automated tools can flag some invalid attributes, but they cannot always judge whether the chosen role, label, state, or relationship matches what the component actually does.
Custom buttons, tabs, dialogs, and expandable elements deserve manual review.

Dynamic Components Need Extra Attention

Many accessibility problems appear only after interaction.
Loading messages, validation errors, notifications, modals, autocomplete results, and live updates may need correct focus handling or screen reader announcements.
These states often look fine visually while remaining unclear to assistive technology.

Manual Verification Completes the Picture

The best workflow combines automation with keyboard testing, screen reader testing, and manual review of important user journeys.
Automated tools are excellent for speed and consistency. Human testing adds context.
The goal is not simply to remove scanner warnings. It is to make sure users can understand the interface, interact with it, and complete the task successfully.