Best way to see what inline JS is executing?

One of the sites I work on has this continuous JS execution line on the root HTML document, which I assume is from inline JS. We have a lot of inline JS though, and my JS knowledge isn’t strong enough to view the code and deduce what is executing.

Is there a tool or method that could help me figure out what part of the document is executing JS? I tried the processing timeline in WPT and I don’t understand it or even know if it’s intended for this task.

Also, what does it mean when the pink line increases or decreases in height?


On the main results page, it should be possible to click on a link to open the devtools view which will show you what code is being executed.

I’m not sure it is worth worrying about though. The skinny line means the code running is likely sub-millisecond and not causing any jank or blocking issues. My guess is that there is a requestAnimationFrame() loop of some kind, maybe to measure interactivity itself.

Hi Patrick,

I have looked at the devtools timeline before, but I’m still learning about what it all says and how to get the best use out of it. Thanks for your answer, at least I know I’m on the right track!