What means that purple line?

[pmeenan]

The purple "line" is actually a bar that spans from the start to the end of the domContentLoadEvent (if a lot of code executes it can end up quite wide, spanning seconds even).

As far as finishing processing the onload event, yes that is loadEventEnd in the metrics (though the DocTime would be better even though it is the start of the load event). The navigation timing entries won't handle javascript redirects and a few other edge cases that the DocComplete time would.

That said, the end of the onload event is a HORRIBLE proxy for being fully interactive.