How to Do Manual Accessibility Testing: 5 Essential Tests
Step-by-step guide to manual accessibility testing. Learn keyboard testing, screen reader basics (NVDA, VoiceOver), zoom testing, and cognitive accessibility review.
Automated accessibility tools catch about 30-40% of WCAG issues. The rest require human judgment. This guide walks you through the five essential manual tests every developer and QA professional should perform.
The 5 Essential Manual Tests
Total time: 50-75 minutes for a thorough manual audit of key pages
1. Keyboard Navigation Testing
Put your mouse aside. Everything on your website should be usable with just a keyboard. This is essential for users with motor disabilities who can't use a mouse.
Essential Keyboard Commands
Tab through the entire page
Press Tab repeatedly from the top of the page to the bottom
What to look for
- Every interactive element (links, buttons, form fields) receives focus
- Focus order follows a logical reading order (usually left-to-right, top-to-bottom)
- No elements are skipped unexpectedly
- Focus never gets "stuck" in one area (keyboard trap)
Activate buttons and links
Press Enter on links and Enter/Space on buttons
What to look for
- All buttons respond to both Enter and Space keys
- Links activate with Enter key
- Custom buttons (divs styled as buttons) work with keyboard
Navigate form controls
Use Tab, Space, Arrow keys in forms
What to look for
- Radio buttons navigate with Arrow keys within the group
- Checkboxes toggle with Space
- Dropdown menus open with Enter/Space and navigate with Arrows
- Date pickers are fully keyboard accessible
Test modal dialogs
Open modals and test keyboard behavior
What to look for
- Focus moves into the modal when opened
- Focus is trapped inside modal (Tab cycles within)
- Escape key closes the modal
- Focus returns to trigger element when closed
Check focus visibility
Watch for visible focus indicators as you Tab
What to look for
- Every focused element has a visible outline or highlight
- Focus indicator has sufficient contrast (3:1 minimum)
- Focus is never hidden by other elements (sticky headers, banners)
Common Keyboard Failures
- • Custom dropdown menus that only work with mouse clicks
- • Carousels without keyboard controls
- • Focus indicators removed with
outline: none - • Modal dialogs that don't trap focus properly
2. Screen Reader Testing
Screen readers convert visual content to speech or braille output. Testing with one reveals how blind and low-vision users experience your site.
Choose Your Screen Reader
Built into macOS. Press Cmd + F5 to enable.
Pre-installedNVDA Commands
VoiceOver Commands
VO = Control + Option
What to Test with a Screen Reader
Page Structure
- • Do headings form a logical outline?
- • Are landmark regions announced (main, nav, footer)?
- • Does the page title describe the content?
Images & Media
- • Is alt text meaningful and descriptive?
- • Are decorative images hidden from screen readers?
- • Do videos have captions/transcripts?
Forms
- • Are all form fields announced with their labels?
- • Are required fields indicated?
- • Are error messages announced?
Interactive Elements
- • Do buttons announce their purpose?
- • Are link destinations clear from the link text?
- • Are expanded/collapsed states announced?
3. Visual & Zoom Testing
Many users with low vision use zoom or text enlargement. Your site should remain usable at 200% zoom without horizontal scrolling.
200% Browser Zoom
How to Test
- Press Ctrl/Cmd + Plus to zoom to 200%
- Or use browser View > Zoom menu
What to Look For
- All content remains visible without horizontal scrolling
- Text doesn't overlap or get cut off
- Interactive elements remain usable
- No content disappears
400% Zoom (for Level AAA)
How to Test
- Zoom browser to 400%
- Test critical user flows
What to Look For
- Content reflows to single column
- Navigation remains accessible
- Forms are still usable
Text Spacing
How to Test
- Use a browser extension or bookmarklet to increase:
- • Line height to 1.5x font size
- • Paragraph spacing to 2x font size
- • Letter spacing to 0.12x font size
- • Word spacing to 0.16x font size
What to Look For
- No text is cut off or overlaps
- Containers expand to fit content
- Buttons and links remain readable
High Contrast Mode
How to Test
- Windows: Settings > Accessibility > Contrast themes
- Or use browser extension for forced colors
What to Look For
- All text remains visible
- Focus indicators still visible
- Icons/graphics with meaning are visible
- Form field boundaries visible
4. Cognitive Accessibility Review
Cognitive accessibility helps users with learning disabilities, attention disorders, or anyone who's tired, distracted, or stressed. This is about clarity and predictability.
Error Messages
- ?Are error messages clear and specific?
- ?Do they explain how to fix the problem?
- ?Are they near the field with the error?
- ?Do they avoid jargon or technical terms?
Instructions & Labels
- ?Are form instructions provided before the form?
- ?Are required fields clearly marked?
- ?Are input formats specified (e.g., MM/DD/YYYY)?
- ?Are labels clear and descriptive?
Navigation & Orientation
- ?Can users easily find where they are in the site?
- ?Are breadcrumbs or other location indicators present?
- ?Is there more than one way to find pages (nav, search, sitemap)?
- ?Is navigation consistent across pages?
Content Clarity
- ?Is language plain and understandable?
- ?Are abbreviations explained on first use?
- ?Is content broken into digestible sections?
- ?Are headings descriptive of their content?
Timeouts & Interruptions
- ?Are users warned before session timeouts?
- ?Can users extend time limits?
- ?Can auto-playing media be paused?
- ?Are animations respectful of reduced motion preferences?
5. Content & Media Review
This test checks the quality of content that automated tools can detect exists but can't evaluate for meaning.
Content Checklist
Alt Text Quality
- • Does alt text convey the purpose of the image?
- • Is it concise (under 125 characters when possible)?
- • Does it avoid "image of..." or "photo of..."?
- • Do complex images have long descriptions?
Link Text
- • Is link text meaningful out of context?
- • No "click here" or "read more" without context?
- • Do links to same destination have same text?
- • Are PDF/external links indicated?
Video & Audio
- • Do videos have accurate captions?
- • Are captions synchronized properly?
- • Is there an audio description option?
- • Are transcripts available?
Headings
- • Do headings describe the content below?
- • Is there only one h1 per page?
- • Do heading levels follow logical order?
- • Are headings used for structure, not styling?
Quick Reference Checklist
Copy this checklist for your testing workflow:
□ Keyboard: Tab through entire page, verify focus order
□ Keyboard: Activate all buttons/links with Enter/Space
□ Keyboard: Test modal focus trapping and Escape to close
□ Keyboard: Verify visible focus indicators
□ Screen Reader: Check heading hierarchy
□ Screen Reader: Verify all images have meaningful alt text
□ Screen Reader: Test form labels and error announcements
□ Screen Reader: Check landmark regions
□ Visual: Test at 200% zoom, no horizontal scroll
□ Visual: Test with increased text spacing
□ Cognitive: Review error messages for clarity
□ Cognitive: Check navigation consistency
□ Content: Verify link text is meaningful
□ Content: Check video captions accuracy
Frequently Asked Questions
How often should I do manual accessibility testing?
Run manual tests whenever you make significant UI changes, at least quarterly for stable pages, and always before major releases. Automated scans can run continuously, but manual tests should be done by humans with fresh eyes.
Do I need to test with multiple screen readers?
Ideally yes, as screen readers can behave differently. For most projects, testing with NVDA (Windows) and VoiceOver (Mac/iOS) covers the majority of users. JAWS is important for enterprise applications targeting business users.
Should I involve users with disabilities in testing?
Absolutely. Developer testing catches technical issues, but real users reveal practical usability problems. Consider hiring disabled consultants for usability testing, especially for complex applications.
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