v132 · Timing Waterfall

Resource Timing Waterfall

Chrome 132 adds firstInterimResponseStart to Resource Timing — it marks when the first interim (103 Early Hints or 1xx informational) response header arrived. It also reverts a prior change to responseStart so it always marks the first final response header. Select a scenario to see how these timestamps differ on the waterfall.

Scenario:
DNS / connect / TLS
Request sent / waiting
firstInterimResponseStart (new)
responseStart (final header)
Response body
Resource timing waterfall — all timestamps in ms from fetchStart

PerformanceResourceTiming properties

see also