performance improvement hints

As we want to be more opinionated about our data, an idea came up during all hands that I found very interesting.

It was about giving people hints for performance improvement (e.g. in the sidebar). That could be something like You image seems very large. You could save yms with decreasingxMB" in the networking panel orThe function xyz’s self time is same as the total time of the root function. If you would split it up, this could save you xms."

I know, its super hard to get those hints right and find the right use cases, but I think this would help the user of the tool a lot to learn more about best practices.

What are your thoughts on this @gregtatum @digitarald @past @mstange?

[gregtatum]

I agree with Markus on the bar needing to be high, and the potential audience being very different in their needs. The moment you surface a metric, people will start optimizing for that specific metric, so I think a lot of care and attention should be put into what is surfaced. I think the jank marker is one of the best tools we have for general honing in on problems. I’d be worried adding more things to the current UI surface, as I’d be afraid they would be noise.

That said, I do think an “audit” panel could be useful, much like the Lighthouse tool. I think they’ve put a lot of thought and research into that tool, and the types of metrics they expose. That tool is very much geared towards PWA devs, which perf.html isn’t necessarily geared towards.

I would say we should track specific features already on file with an “audits” label, and see if we can collect a good list of features that would meet the needs of an audit panel.

[julienw]

We discussed it today and didn’t feel that it’s useful to keep this issue open as it’s not actionable per se. Giving useful information to our users is still a goal for us, but we should file issues about specific ideas or specific problems.