Cross-browser testing
Checking the same important flows across browser engines, operating systems, and screen sizes to catch compatibility-only bugs.
See it
What it is
Cross-browser testing runs the same important flows across different browser engines, versions, operating systems, and viewport sizes. Chromium browsers use Blink, Firefox uses Gecko, and Safari uses WebKit, so three browser logos do not always mean three independent engines. On iPhones, every browser has historically shipped WebKit underneath, which makes Chrome on iOS a Safari engine wearing a different icon. Playwright can automate Chromium, Firefox, and WebKit from one suite.
Reach for it on login, checkout, uploads, media, complex forms, and CSS or web APIs with uneven support. Choose coverage from real audience analytics and product commitments, then put the critical combinations in CI and leave a wider set for scheduled runs or BrowserStack devices.
Gotcha: shrinking desktop Chrome to 390 pixels tests a viewport, not mobile Safari. Input methods, fonts, permissions, virtual keyboards, and operating-system integrations can differ on real devices. Also remember that Playwright's WebKit build is useful WebKit coverage, but it is not the Safari application.
Ask AI for it
Configure Playwright projects for Chromium, Firefox, and WebKit at desktop 1440x900 plus Pixel 7 and iPhone 15 device profiles. Run the login, checkout, file-upload, and keyboard-navigation smoke tests in each relevant project, collect traces and screenshots on failure, and publish a GitHub Actions matrix summary by browser and viewport. Keep selectors role-based, and mark any flow requiring real Safari or a real mobile device for a separate BrowserStack run.