Web Platform Tests (WPT) is a massive shared test suite that checks whether all major web browsers — Chrome, Firefox, Safari, Edge, and others — behave consistently when displaying websites and web apps. Think of it as a universal quality checklist that browser makers run to confirm their software follows the agreed-upon rules of how the web should work.
// why it matters When browsers behave differently, developers must build workarounds that add cost and slow down shipping — WPT is the industry's shared mechanism for reducing that friction, making the web a more reliable platform for products to run on. For builders, broader browser consistency means less money spent on cross-browser bug fixes and greater confidence that web-based products will reach users as intended, regardless of what device or browser they use.