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rviscomi / ismyhostfastyet

A leaderboard of hosting providers' TTFB performance
https://ismyhostfastyet.com/
GNU General Public License v3.0
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Use web.dev/fcp thresholds #37

Open josephscott opened 3 years ago

josephscott commented 3 years ago

In May there were changes to the TTFB and FCP thresholds - https://groups.google.com/a/chromium.org/g/chrome-ux-report-announce/c/6soDVEEacPM/m/Ny6Z9hwgAgAJ

I'm unsure why the FCP values that were mentioned in there are being used:

FCP
fast: 1500ms (previously 1000ms)
slow: 2500ms (previously 3000ms)

Looking at https://web.dev/fcp/ the "good/fast" breakdown is 1,800 ms or less. Why the the 300 ms difference here?

rviscomi commented 3 years ago

Is the suggestion to change the slow TTFB threshold from 1500 to 1800?

josephscott commented 3 years ago

Perhaps I'm not seeing how https://ismyhostfastyet.com/ is related to the FCP changes. Based on the announcement post I'm trying to figure out what there are different thresholds for what constitutes a "good/fast" FCP number.

rviscomi commented 3 years ago

Generally, having a good TTFB makes it easier to achieve fast FCP/LCP. FYI the CrUX post you linked is from 2020 and has since been superseded by this update.

styfle commented 3 years ago

How about adding a toggle to switch between TTFB/FCP/LCP?

rviscomi commented 3 years ago

I think TTFB is the only metric that can be directly attributed to hosts. FCP/LCP are more measures of front-end performance, so it wouldn't necessarily be reflective of the hosts' back-end performance.

styfle commented 3 years ago

Maybe this section should be updated then because it still says "we plan to add more metrics"

image

rviscomi commented 3 years ago

Yeah good point. I think that section could be updated/removed. I think there is a very limited set of metrics that are relevant to attribute at the host level, and TTFB strikes me as the only metric that is both relevant to hosts and available in the CrUX dataset. If there are new metrics that we could add to CrUX that would enable better host-level insights, I'd love to see those suggestions in the CrUX discussion forum.