UI Testing Checklist: A Complete Guide to Catch Visual Bugs Before Users Do

Your site or peregrine app is & nbsp; a 24/7 storefront. UI testing ensures your audience realise the better version of your job at all times. Done right, it establishes a solid sentience of professionalism that finally transform into better user experience and, of course, revenue.

Here 's a detailed checklist of all the item you take when performing UI examination.

UI testing vs functional testing

Functional examination asks: “ Does it work? ”

UI & nbsp; testing asks: “ Does it appear right? ”

Functional examination validatesbehaviors: button chink, form submissions, information flows. It ascertain whether your app responds aright to user input and occupation logic.

UI testing validates & nbsp;perception:Layouts, colours, spacing, picture placement. These are the insidious clue users rely on to feel convinced in your brand. And while your app mightfunctionmerely fine, one broken layout or off-brand font can instantly gnaw trustfulness.

In other language, UI testing & nbsp; catches what functional testing can ’ t.

Why functional tests ca n't catch UI bugs?

Here ’ s the haul: most traditional tests don ’ t actuallysee your UI.

Even if you feature 100 % code coverage with unit and functional tests, none of them are checking how your applooksafter a change. They won ’ t catch a misaligned push, a missing image, or text that overlaps on smaller blind.

And when changes are merged chop-chop (think: CSS tweaks, layout refactors, font ascent), visual bugs can creep in without breaking a single test. That ’ s how regressions slip past QA unnoticed until a existent user complains.

UI testing direction specifically on the optic part of the site. It actually complements what functional testing want.

UI testing complete checklist

1. Basic Application Functionality

• Ensure all pages and screens load without console or network errors

• Validate working state of core functionality (logins, modals, form submissions)

• Test touch/click responsiveness across buttons, icons, and links

• Verify biometric authentication (Face ID, Touch ID) induction appropriately

• Validate state retention: local storage, session data, cookies

• Confirm kind validation triggers with appropriate error messaging

2. UI Compatibility Across Platforms

• Test on native Android (latest stable and one version prior)

• Test on aboriginal iOS (late stable and one version prior)

• Test on hybrid/webview setting if applicable

• Verify platform-specific UI constituent (e.g., bottom sheets, back gestures)

• Validate that fonts, borders, and picture furnish correctly on all Operating Systems

📚 Read More: & nbsp;Cross-browser Testing: A Complete Guide

3. UI Compatibility Across Screen Sizes

• Test responsiveness on popular screen resolutions:

  • Mobile: iPhone SE, iPhone 15 Pro Max, Pixel 7, Samsung Galaxy S22

  • Tablet: iPad Air, Galaxy Tab

  • Desktop: 1366x768, 1440x900, 1920x1080, 2560x1440

• Confirm layout consistency in both portrait and landscape orientation

• Check that modals, sidebar, and sliders behave as expected

• Ensure elements don ’ t time, overflow, or vanish on narrow screens

  Pro tip: Tools like SUSA can handle this autonomously — upload your app and get results without writing a single test script.

• Validate breakpoints for grid and flex layout

4. Performance & amp; Scalability

• Measure page and screen payload time

• Test UI under different net conditions (3G, 4G, offline)

• Use lazy loading for images and components below the fold

• Confirm app behavior under high traffic or model cargo

• Test install/uninstall cycles on mobile

• Monitor memory and CPU impact during extended use

📚 Read More:Performance Testing vs. Load Testing

5. Mobile App Accessibility

• Ensure screen reader compatibility (VoiceOver, TalkBack)

• Check that all UI ingredient are keyboard-navigable

• Validate focus outlines and tab sequence for inputs and controls

• Confirm discernability: font size, text scale support

• Check contrast ratios meet WCAG 2.1 AA compliance

• Test accessibility shortcuts and alternate text on all elements

📚 Read More:Accessibility Testing: A Complete Guide

6. Geolocation Testing

• Simulate locating from different regions using a VPN or instrument

• Test language and currency display updates by region

• Validate region-specific banners, features, or T & amp; Cs

• Ensure geolocation permission are requested gracefully

• Simulate time zone shifts and verify correct date/time display

7. Color Checks

• Verify all make color codes (hex/RGB) match design scheme

• Test hover, focusing, and active states have open colouration note

• Check hyperlink color differentiates visited/unvisited province

• Simulate colorblindness fashion (protanopia, deuteranopia)

• Validate consistency in dark mode or high-contrast themes

8. Typography Errors

• Confirm font family, size, and weight per design spec

• Check for coherent line peak, spacing, and kerning

• Review text wrap and truncation on all screen size

• Validate heading hierarchy and reproducible formatting

• Ensure upper/lowercase usage is grammatically correct

• Check for spelling and grammar issues throughout the UI

9. Navigation Speed

• Confirm header and side sailing loads within 1–3 seconds

• Test lazy loading for menus and infinite scroll elements

• Validate menu responsiveness under low web speeds

• Measure First Contentful Paint (FCP) and Largest Contentful Paint (LCP)

• Ensure no janky transitions during navigation

10. Image Alignment

• Ensure banner, hero, and slider images are properly size and centre

• Validate icons are sharp and correctly positioned at all DPIs

• Confirm image carousels are touch and click responsive

• Check alt tags for accessibility compliance

• Validate pullout image behavior when loading fails

• Confirm images are optimise for file size and format