Microsoft Edge Origin Trials Developer Console

To help web applications compute end-to-end telemetry for protocol launches we propose adding 2 new fields userAgentStart and protocolLaunchStart to the PerformanceNavigationTiming object. The parameter userAgentStart corresponds to a timestamp captured early in the startup of the browser application. The parameter protocolLaunchStart corresponds to the time when user action that initiated the protocol launch in the non-browser client application. For cold starts; when no browser process has yet been created; the protocolLaunchStart value will be lesser than the userAgentStart value. For warm starts; where one or more browser processes are already running; the protocolLaunchStart value may be higher than the userAgentStart value. These new fields are only populated for protocol launches. Learn more