Rendering engines: a comparison
The rendering engine interprets HTML, CSS and JavaScript. Test at least one browser per engine and check your audience mix (StatCounter).
| Engine | Browsers | Caveats | Resources |
|---|---|---|---|
| Blink | Chrome, Edge, Opera, Brave, Vivaldi, Samsung Internet | Dominant engine; new APIs often land first (e.g. Speculation Rules); excellent DevTools. Brave blocks ads and trackers: test with blocking on. | Chrome Platform Status |
| Gecko | Firefox, Waterfox | Independent engine, strong standards compliance. A site that works on Firefox usually works on Waterfox. | MDN |
| WebKit | Safari (macOS, iOS) | Default engine on iOS; alternative engines are possible in some jurisdictions (EU), so check current status. Test on real devices: vh/svh, scrolling, recent APIs. | WebKit Blog |
Core Web Vitals are measured in Chrome (CrUX): see Core Web Vitals. Also check lazy loading and image formats on each engine.