Full Pass of Acid3
Today we would like to announce that WebKit is the first browser engine to fully pass Acid3. A while back, we posted that we scored 100/100 and matched the reference rendering. Now, thanks to recent speedups in JavaScript, DOM and rendering, we have passed the third condition …
Context & Ripple Effects
This closes a standards-compliance race that had been running all year: Microsoft had earlier celebrated Internet Explorer 8 passing the older Acid2 test as a milestone, while Apple's engine had been stacking up capabilities in releases like WebKit 3's ten new tricks. Scoring 100/100 on Acid3 wasn't enough — the third condition required matching the reference rendering within strict time limits, which is why the recent JavaScript, DOM, and rendering speedups matter as much as the correctness work.
First-order effects
- WebKit becomes the first browser engine to fully pass Acid3 — not just scoring 100/100 but meeting the dynamic timing condition — giving Apple/Safari an immediate standards-compliance bragging right over Gecko, Presto, and Trident.
- The pass is explicitly credited to performance work (JavaScript, DOM, rendering speedups), meaning the same optimizations ship directly into everyday browsing, not just the test harness.
Second-order effects
- Competitors are forced to chase the same target, and the win feeds straight into the benchmark war that follows — by early 2009 Apple is marketing Safari 4 as 42x faster than IE 7 while Google's Chrome, built on the same open-source WebKit core, is climbing past Safari in market share.
- Acid-style tests become marketing currency rather than niche developer tools, pressuring every engine vendor to treat conformance plus raw speed as a public scoreboard.
Third-order effects
- Standards compliance stops being differentiating and becomes table stakes, shifting browser competition onto sustained performance benchmarks — a pattern that persists for over a decade, down to today's fights over who tops WebKit's own Speedometer 2.0 benchmark.
- If engines keep racing to satisfy ever-harder automated tests, the web platform itself consolidates around a de facto spec enforced by benchmarks and conformance suites rather than by any single vendor's roadmap.
The trend: Browser competition is migrating from feature checklists toward standardized conformance-plus-speed benchmarks as the primary arena where engines prove superiority.