Accessibility & Usability Testing Interview Questions for Software Testing
32 Accessibility & Usability Testing questions with answers for software testing roles — 10 easy, 15 medium, 7 hard.
About Accessibility & Usability Testing
This topic covers testing whether everyone, including people with disabilities, can use a product easily. Expect questions on WCAG 2.2 levels, keyboard-only navigation, screen readers, colour contrast, forms, dialogs and automated scanners, plus usability heuristics, user sessions and metrics like SUS. Accessibility is now a legal and contract requirement for many products, so testers who can find and report these issues stand out.
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WCAG, the Web Content Accessibility Guidelines from the W3C, is the main standard for making web content usable by people with disabilities. The current version is WCAG 2.2. It has three conformance levels: A is the minimum, AA is the usual legal and contract target, and AAA is the highest and rarely required for a whole site. Each level adds success criteria, such as colour contrast at AA.
POUR is the four principles behind WCAG. Perceivable: users can see or hear the content, for example images have alt text and videos have captions. Operable: everything works with a keyboard and users have enough time. Understandable: text is clear and forms explain errors. Robust: content works with assistive technologies such as screen readers. Every WCAG success criterion sits under one of these four principles.
03
What is the difference between accessibility testing and usability testing?
Accessibility testing checks that people with disabilities can use the product, often against WCAG criteria, using keyboards, screen readers, zoom and contrast tools. Usability testing checks how easily typical users complete tasks, by watching real users and measuring success, time and errors. They overlap, since clear labels help everyone, but a page can pass WCAG and still be confusing, or be easy for most users yet unusable with a screen reader.
04
How do you test a web page using only the keyboard?
Put the mouse away. Press Tab and Shift+Tab to move through every link, button and field, and check that the order is logical and the focus outline is always visible. Use Enter and Space to activate buttons and links, arrow keys for menus, radio groups and sliders, and Escape to close dialogs. Check that nothing traps focus, hidden items do not receive focus and a skip to main content link works.
05
What is a screen reader and which ones are commonly used for testing?
A screen reader is software that reads screen content aloud or sends it to a braille display, used mainly by blind and low-vision people. Common ones are NVDA, a free Windows reader, JAWS, a paid Windows reader common in enterprises, VoiceOver, built into macOS and iOS, and TalkBack, built into Android. Testers usually cover NVDA with a desktop browser plus VoiceOver or TalkBack on mobile.
Alt text gives a text alternative for images so screen reader users get the same information. Check that informative images have short, meaningful alt text, such as 'Bar chart showing sales doubled in 2025', that decorative images have empty alt so they are skipped, and that image buttons describe the action, such as 'Search', not the picture. Inspect the alt attribute in developer tools and listen with a screen reader.
07
What are focus order and visible focus, and how do you test them?
Focus order is the sequence in which keyboard focus moves through interactive elements; it should follow the visual reading order. Visible focus means the focused element clearly shows a ring or highlight. Test by pressing Tab through the page and watching where focus goes. Common bugs are focus jumping to the footer, focus going behind an open dialog and designers removing the outline with CSS, leaving keyboard users lost.
A keyboard trap is when focus moves into a component and the user cannot move out using the keyboard, for example an embedded video player or date picker that captures Tab forever. Mouse users never notice, but keyboard and screen reader users are stuck and must reload the page. It fails WCAG criterion 2.1.2. Test every widget by tabbing in and out, and check that Escape closes popups and returns focus.
09
Explain three usability heuristics with examples from a web app.
Visibility of system status: after clicking Pay, show a progress indicator so users do not click again. Error prevention: disable the Submit button until required fields are valid, or ask for confirmation before deleting an account. Recognition rather than recall: show recently searched items and saved addresses instead of making users remember them. Other heuristics include consistency, user control with undo, and clear help for recovering from errors.
10
A dashboard shows pass or fail status only with red and green dots. What is the issue?
This relies on colour alone to give information, which fails WCAG criterion 1.4.1. Users with red-green colour blindness, which affects a noticeable share of men, cannot tell the states apart, and screen readers announce nothing. Recommend adding text or icons such as a tick and a cross with labels like 'Passed' and 'Failed', and accessible names for the dots. Test with a colour blindness simulator in browser developer tools.
Turn on the screen reader, for example NVDA with a browser, and listen rather than look. Navigate by headings to check the structure is logical, by landmarks to find main regions and by Tab through controls. Each control should announce a clear name, role and state, such as 'Subscribe, checkbox, not checked'. Check images, form errors, dynamic updates like cart counts and dialogs. Note exactly what was announced in bug reports.
12
What is colour contrast ratio and what values does WCAG require?
Contrast ratio compares the brightness of text and its background, from 1:1 to 21:1. WCAG AA requires at least 4.5:1 for normal text and 3:1 for large text, which is about 18 point or 14 point bold. User interface parts such as input borders and icons need 3:1. AAA raises text to 7:1. Testers check this with a contrast checker or browser developer tools, including placeholder, disabled and hover states.
13
How do you test form accessibility, including labels and error messages?
Check that every field has a visible label tied to it, so clicking the label focuses the field and a screen reader announces it. Required fields must be indicated in text, not only by colour or an asterisk without explanation. Submit with errors and check that messages are specific, appear next to the field, are announced by the screen reader and focus moves to the first error. Also check autocomplete for name, email and address.
14
What automated accessibility tools exist and what are their limits?
Common tools are axe DevTools, Lighthouse in Chrome, WAVE and accessibility linters in CI. They quickly catch missing alt text, low contrast, missing labels and invalid ARIA. Their limit is that they find only roughly a third of WCAG issues. They cannot judge whether alt text is meaningful, focus order is logical, error messages make sense or a custom widget works with a screen reader, so manual testing is still required.
Set browser zoom to 200 percent and check that all text is readable and no content or buttons are cut off. Then zoom to 400 percent, or use a 1280 pixel wide window, which gives a 320 CSS pixel viewport; content should reflow into one column without horizontal scrolling, except for things like data tables and maps. Also increase text spacing and the operating system font size to check that labels do not overlap.
16
A training portal is adding recorded video lessons and podcasts. What accessibility checks do you run?
Check that prerecorded videos have accurate, synchronised captions, not just auto-generated ones with errors, and that audio-only content like podcasts has a transcript. Important visual information that is not spoken should have audio description or be covered in the transcript. Media should not autoplay with sound, and player controls must work by keyboard and be announced by screen readers. Also check that nothing flashes more than three times per second.
17
What is heuristic evaluation and how is it different from a usability test with users?
Heuristic evaluation is an expert review where a few evaluators inspect the interface against known usability principles, such as Nielsen's ten heuristics, and list problems with severity. It is fast and cheap and needs no participants. A usability test watches real users perform tasks and shows where they actually struggle. Heuristic reviews find many obvious issues early, but they can miss problems that only real users with real goals reveal.
18
How do you run a moderated usability test session?
Define goals and three to five realistic tasks, such as 'Book a train ticket for next Friday'. Recruit participants who match real users. In the session, explain that you are testing the product, not them, ask them to think aloud, and avoid hinting even when they struggle. Record the screen with consent, note where they hesitate or fail, and finish with a short questionnaire. Then group findings by severity and frequency.
19
A CAPTCHA on the signup page blocks screen reader users. What do you recommend?
Log it as a high-severity accessibility bug because it fully blocks a group of users from signing up. An image-only CAPTCHA fails WCAG unless an alternative is offered. Recommend options such as invisible or risk-based bot checks, an email or OTP verification step, an audio alternative plus another modality, and rate limiting on the server. Retest the full signup with NVDA and TalkBack after the change.
20
A screen reader announces 'button, button, button' on a toolbar. What is the bug and how do you report it?
The toolbar uses icon-only buttons without accessible names, so users hear the role but not the purpose. Report it with the page, the screen reader and browser versions, the exact announcement and the expected one, such as 'Bold, toggle button, not pressed'. Reference WCAG 4.1.2 Name, Role, Value. The fix is an aria-label or visually hidden text on each button, plus a tooltip that also helps sighted users.
21
Your automated accessibility scan shows zero errors. Is the page accessible?
Not necessarily. Automated tools catch only a part of WCAG issues, such as missing labels and contrast. A clean scan still needs manual checks: keyboard-only navigation, focus order, a screen reader pass, meaningful alt text and link names, error handling, zoom and reflow and dynamic content. Report the result as 'no automated violations found' and add the manual checklist outcome before claiming conformance.
Give a clear title, such as 'Checkout: Place Order button not reachable by keyboard'. Include the page URL, browser, operating system and assistive technology with versions. Write exact steps, what was announced or happened, and what was expected. Add the WCAG success criterion, such as 2.1.1 Keyboard, and the user impact. Attach a screenshot or audio recording, and suggest a fix when obvious. Severity should reflect whether users are fully blocked.
23
How do you test touch target size and gestures for accessibility in a mobile app?
Check that buttons and icons are large enough to tap without hitting neighbours: Android guidance is 48 by 48 dp and iOS is 44 by 44 points. Test with large font settings and one-handed use. Any action using complex gestures, such as swipe to delete or pinch, must have a simple tap alternative. Then turn on TalkBack and VoiceOver and confirm each control can be focused, named and activated.
24
Tell me about a time you pushed for an accessibility fix the team wanted to postpone.
Situation: before a release, I found the payment form errors were not announced by screen readers and not reachable by keyboard. Task: the team wanted to defer it. Action: I recorded a short NVDA video showing a user could not finish payment, linked it to WCAG and our customer commitments, and proposed a small fix. Result: the fix took half a day, shipped in the release and we added keyboard checks to our definition of done.
25
Tell me about a time you found a usability problem that the requirements did not mention.
Situation: while testing a leave application form, every test case passed. Task: I still felt the flow was confusing. Action: I noticed the date picker started on Sunday and the half-day option was hidden under 'More', so I asked two colleagues to apply for leave while I watched; both made mistakes. I logged a usability suggestion with notes. Result: product moved the option and support queries dropped.
ARIA, Accessible Rich Internet Applications, is a set of HTML attributes such as role, aria-label, aria-expanded and aria-live that tell assistive technology what a custom component is and what state it is in. The first rule is to prefer native HTML elements, such as a real button, because they are accessible by default. Wrong ARIA is worse than none, so testers verify announced roles and states match real behaviour.
Open the dialog with the keyboard. Focus should move into it, usually to the first field or heading, and the screen reader should announce it as a dialog with its title. Tab must stay inside the dialog while it is open and the page behind must not be reachable. Escape and the close button should close it, and focus must return to the button that opened it. Also check it reads correctly when zoomed.
SUS is a standard ten-question survey that users answer on a five-point agree to disagree scale after using a product. The answers are converted to a score from 0 to 100. A score around 68 is considered average, above about 80 is good and below 50 signals serious usability problems. It is quick and comparable across releases, but it gives a score, not reasons, so teams pair it with observation notes.
29
Analytics show many users drop off at step three of a five-step checkout. How do you investigate the usability problem?
First look at what step three asks: maybe address entry, a surprise delivery charge or forced signup. Check analytics for errors, rage clicks and time spent, and watch session recordings if available. Test it yourself on mobile and slow networks. Then run a quick usability test with five users on that step. Present evidence with likely causes and options, such as guest checkout or showing charges earlier, and measure after the change.
30
A client needs WCAG 2.2 AA compliance before launch in two weeks. How do you plan the testing?
Agree on scope: key user journeys and page templates, not every page. Day one, run automated scans on all templates to fix easy issues fast. Then do manual checks of each journey with keyboard, NVDA, VoiceOver on mobile, zoom and contrast. Log issues with WCAG references and severity, and get blockers fixed first. Retest fixes and deliver a conformance summary with known issues. Be honest if full compliance is not realistic.
31
Which accessibility laws and standards matter for products used in India and abroad?
In India, the Rights of Persons with Disabilities Act 2016 requires accessible information and communication technology, and government sites follow the GIGW guidelines, which align with WCAG. Abroad, the US uses the ADA and Section 508, Europe uses EN 301 549, and the European Accessibility Act applies to many digital products and services from June 2025. Most of these point to WCAG AA as the practical testing target.
32
What new success criteria in WCAG 2.2 should testers know?
WCAG 2.2, published in 2023, added criteria including Focus Not Obscured, so sticky headers must not hide the focused element; Dragging Movements, which needs a non-drag alternative; Target Size Minimum of 24 by 24 CSS pixels; Consistent Help placement; Redundant Entry, so users are not asked for the same information twice; and Accessible Authentication, which avoids memory puzzles at login. It also removed the old Parsing criterion.
Frequently asked questions
How important is Accessibility & Usability Testing in Software Testing interviews?
This topic covers testing whether everyone, including people with disabilities, can use a product easily. Expect questions on WCAG 2.2 levels, keyboard-only navigation, screen readers, colour contrast, forms, dialogs and automated scanners, plus usability heuristics, user sessions and metrics like SUS. Accessibility is now a legal and contract requirement for many products, so testers who can find and report these issues stand out.
How should I use the Accessibility & Usability Testing sheet?
Go top to bottom — easy to hard. Answer before opening each answer, tick what you solved and save misses to Last-Minute Revision.