Web users use different browsers—Chrome, Firefox, Safari, Edge—and they all behave a little differently. That’s why you need to test across multiple browsers. A site that works fine in Chrome might break in Safari.

To do cross-browser testing, first pick the browsers your users care about. For most apps, testing in the top three or four is enough. Then use tools like Selenium Grid, BrowserStack, or Playwright to run tests across them.

Set up your automation scripts to run the same tests in each browser. Watch for layout issues, missing elements, or broken functionality. Even small CSS differences can affect usability.

Don’t try to catch every browser bug. Focus on key workflows and make sure nothing critical breaks. Cross-browser bugs are often subtle but easy to catch with automated visual checks or good selectors.

Test both headless and headed when needed. Sometimes things render differently in headless mode. And always double-check mobile viewports if your site supports phones or tablets.