These charts measure how many WPT tests fail in exactly one browser (of the three major engines - Chromium, Gecko, WebKit), or "Browser Specific Failures". Such tests are interesting as they mostly represent 'real' interop issues in agreed-upon web features.
(Click + drag on graphs to zoom, right click to un-zoom)
Results are from stable releases of browsers at the given date, with a minimal set of flags passed to enable testing.
wpt.fyi queryNotable dates:
Results are from experimental releases of browsers at the given date, such as Safari Tech Preview. Where appropriate, experimental features are enabled (e.g. --enable-experimental-web-platform-features for Chrome.)
wpt.fyi queryNotable dates: