Why One Tool Is Not Enough
No single tool tests everything. Automated scanners, browser extensions, screen readers and full platforms each catch different problems, so most teams use more than one.
Types of Accessibility Tools
- Automated Scanners: These tools crawl your website and programmatically check for common accessibility violations (e.g., missing alt text, poor contrast, missing ARIA attributes). They are fast, but no tool finds everything: in a 2017 UK Government Digital Service test, the best single tool found 41% of the barriers on a deliberately inaccessible page.
- Browser Extensions: Tools like axe DevTools or WAVE allow developers to test individual pages while they are building them.
- Manual Testing Tools: Tools that assist human testers, such as screen readers (NVDA, JAWS, VoiceOver), color contrast analyzers, and keyboard focus simulators.
- Platforms: Tools like AccessiSight combine automated detection, manual testing checklists, and compliance reporting (VPAT generation) in one place.
Choosing between them
- Automated scanners are best for catching regressions on every deploy and for covering many pages quickly.
- Browser extensions are best while you build a single page, because you see issues in context.
- Screen readers and keyboard testing are the only way to know how a page actually feels to use. NVDA (Windows) and VoiceOver (macOS, iOS) are free.
- Platforms that combine scanning, reporting and manual checklists help when several teams share the work.
We make AccessiSight, which is one of these platforms, so we won't rank tools here. Try two or three on your own pages and compare what they find.
Why Automated Testing Isn't Enough
Even the best automated tools cannot test for context or intent. For example, a tool can check if an image has an alt attribute, but it cannot tell if the description accurately describes the image's meaning in the context of the page. Manual testing by experts and users with disabilities remains essential.