Cross-Browser Testing
Testing that verifies a website or web application renders and functions correctly across different browsers, browser versions, and operating systems.
Despite modern web standards, browsers still interpret HTML, CSS, and JavaScript with subtle differences. Cross-browser testing identifies these inconsistencies before users do. Teams typically define a browser matrix based on their analytics data, prioritizing the browsers and versions their actual visitors use.
Testing can be performed manually using services like BrowserStack or LambdaTest, or automated using tools like Playwright (which supports Chromium, Firefox, and WebKit) or Selenium Grid.
Why It Matters for QA Teams
A site that works perfectly in Chrome may have broken layouts in Safari or missing functionality in Firefox. Cross-browser testing ensures a consistent experience for all visitors, not just those using the development team's preferred browser.
Example
A QA team discovers that a CSS backdrop-filter: blur() effect used on a modal overlay does not render in Firefox versions below 103. They flag the issue, and the team adds a fallback semi-transparent background for unsupported browsers.