← back to v133 · resource-timing-revert-responsestart-change-and-introduce-firstresponseheadersst

conformance · v133

v133 · resource-timing-revert-responsestart-change-and-introduce-firstresponseheadersst — conformance probe

5 assertions drawn from the spec. Each is a single contract the spec text makes. Pass/fail reflects what this browser executed; blocked means the contract was not run because it needs user mediation, hardware, or another unavailable precondition. Open the page in Chrome stable / canary / Firefox / Safari to compare.

browser: spec: https://w3c.github.io/resource-timing/#dom-performanceresourcetiming-finalresponseheadersstart chromestatus: #5158830722514944 generated 2026-06-01T08:12:59Z by conformance-author-v1-subagent
0
pass
0
fail
0
blocked
5
total
id contract kind verdict detail
performance-resource-timing-exposed PerformanceResourceTiming is exposed. exists
responsestart-still-on-prototype responseStart remains on PerformanceResourceTiming.prototype (reverted to its pre-regression meaning). script
firstinterimresponsestart-on-prototype PerformanceResourceTiming.prototype exposes firstInterimResponseStart for the first interim (e.g. 103 Early Hints) response. spec ↗ script
finalresponseheadersstart-on-prototype PerformanceResourceTiming.prototype exposes finalResponseHeadersStart for the final response's header bytes. spec ↗ script
supportedentrytypes-includes-resource PerformanceObserver.supportedEntryTypes includes 'resource'. script