Is there a way to get the firstPaint reported by Firefox (does FF even export it in the HAR) ? All Firefox HARs I’m looking at (both from a private and public instances), have [“log”][“pages”]["_firstPaint"] == 0 . Is that the right place to try to extract it from?
Also a relevant question regarding StartRender (which is consistently reported from all browsers) : Since (as far as I know) it is based on captures of 100ms intervals, what does the fact that it’s not always multiples of 100 mean? Does the timer start when the browser is opened / when the navigation starts? And in case of a WPT script, does it start at one of those times, or can “logData 0/1” affect it?