Strange values for total number of React origins

I’m using the excellent Core Web Vitals Technology Report that @rviscomi created. When looking at the total number of origins for React I see a significant drop in July 2020 from 385K to 200K. Likewise in July 2021 I see a huge increase from 242K to 470K. Otherwise the values are fairly stable: Core Web Vitals Technology Report Any idea what could have caused such fluctuations? This makes me hesitant to trust the performance data for React.

I’m going to try to think of an explanation for the drop, meanwhile here’s a visual that helps to describe the change we’re talking about:


Interesting to see the number of desktop origins less affected by the change in July 2020.

My guess would be the June fix to the JS detections:

As for the dip, probably changes in the definitions that relied on code changes that wasn’t caught.

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Yes… @rviscomi … We discussed this as part of this issue and @patmeenan applied the fix in Jun-2021 (See this issue from this comment onwards - Wappalyzer Technologies table has unexpected entries · Issue #1843 · HTTPArchive/ · GitHub)

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Agreed with @patmeenan and @rockeynebhwani that the fix from June 2021 seems to explain the sharp recovery.

@DanShappir I’d suggest focusing on results after July 2021 if possible. For earlier results, some technologies might not have been detected properly. That said, React was still detected on hundreds of thousands of sites so the aggregate CWV data isn’t entirely useless, it’s just a different subset of the full detections.

Cool! Thank you for the quick explanation.
I agree that I can use the performance data from before that fix.