Software Testing - Cross-Browser Testing

1. What is Cross-Browser Testing?

Cross-Browser Testing is the process of checking whether a website or web application works correctly and consistently across:

  • Different browsers (Chrome, Firefox, Safari, Edge, Opera, etc.)

  • Different browser versions

  • Different devices (desktop, mobile, tablet)

  • Different operating systems (Windows, macOS, iOS, Android, Linux)

It ensures that all users get the same functionality and UI experience no matter what browser they use.

2. Why is Cross-Browser Testing Important?

✔ Different browsers interpret HTML, CSS, and JavaScript differently

(e.g., Safari may render animations differently from Chrome)

✔ Prevents UI/UX issues

Buttons, forms, layouts, images may appear broken in some browsers.

✔ Ensures functionality consistency

Login, forms, navigation, popups, carts, etc. must work everywhere.

✔ Supports older browser versions

Some users may use outdated versions.

✔ Builds trust and improves user experience

A bug-free website increases retention and conversions.

3. What to Test in Cross-Browser Testing?

1. Functional Testing

  • Form submission

  • Validation messages

  • Links

  • Navigation menus

  • Buttons

  • API calls

2. UI Testing

  • Layout alignment

  • Fonts and typography

  • Colors and themes

  • Spacing and padding

  • Images and icons

  • Responsiveness

3. Performance Testing

  • Page load time

  • Smooth animations

  • Rendering speed

4. Compatibility Testing

  • CSS compatibility

  • JavaScript compatibility

  • HTML5 support

  • Cookies and cache behavior

5. Accessibility Testing

  • Screen reader behavior

  • Keyboard navigation

4. Browsers Commonly Used for Testing

Desktop Browsers

  • Google Chrome

  • Mozilla Firefox

  • Safari (macOS)

  • Microsoft Edge

  • Opera

Mobile Browsers

  • Chrome for Android

  • Safari for iOS

  • Samsung Internet

  • UC Browser (some regions still use it)

5. Approaches to Cross-Browser Testing

1. Manual Testing

Test pages on real browsers manually to verify:

  • UI accuracy

  • Functional operation

  • Responsiveness

2. Automated Testing

Use automated scripts to run tests on multiple browsers.
Tools like Selenium support:

  • Parallel testing

  • Automated suites

  • Quick execution

3. Cloud-Based Testing

Platforms provide hundreds of browser/OS combinations:

  • Run on real devices

  • Access older browser versions

  • No installation required

6. Tools for Cross-Browser Testing

You can perform cross-browser testing using:

Open-Source Tools

  • Selenium WebDriver

  • Playwright

  • Cypress (supports limited browsers)

Cloud Testing Platforms

  • BrowserStack

  • LambdaTest

  • Sauce Labs

  • CrossBrowserTesting.com

These tools allow testing on:

  • Different OS

  • Different device types

  • Multiple browser versions

7. Cross-Browser Testing Strategy (Step-by-Step)

Step 1 — Identify your target audience browsers

Check analytics to know which browsers users use most.

Step 2 — Create a Browser Compatibility Matrix

Include:

  • Browsers

  • Versions

  • OS combinations

  • Devices

Step 3 — Prioritize Browsers

High-traffic browsers get priority.

Step 4 — Test Critical Functionality

Test:

  • Login

  • Checkout

  • Navigation

  • Forms

Step 5 — UI & Layout Testing

Check responsiveness on various devices.

Step 6 — Automate repeating tests

Use Selenium, Playwright, or cloud platforms.

Step 7 — Log issues with screenshots & videos

Step 8 — Re-test after fixes

8. Common Issues Found in Cross-Browser Testing

  • CSS styles not applied consistently

  • Layout breaking on Safari or Firefox

  • JavaScript functions not supported

  • Font rendering differences

  • Vendor-specific prefixes required (-webkit-, -moz-)

  • Input fields behaving differently

  • Flexbox and grid alignment issues

  • Video/audio not supported on certain browsers

  • Popups not opening or functioning properly

9. Best Practices

  • Always test on real browsers instead of simulators

  • Cover at least top 5 browsers based on analytics

  • Include mobile browsers

  • Use responsive design testing

  • Test with JavaScript ON and OFF

  • Validate pages on older versions

  • Automate repeated tests to save time

  • Maintain a compatibility checklist