Google appears to have updated its Core Web Vitals metrics within Google Search Console a few days ago. The weird thing is that good URLs and URLs need improvements metrics all went down around that date but the poor URLs stayed the same.
Rafael Rubio posted about this on X and he seems to be right. I checked a number of random sites I have access to in Search Console and they all seem to shwo the good URLS and URLs need improvements dropping around July 11th or so.
Google's John Mueller responded to the questions about these changes and pretty much said these are normal and this is not some sort of bug. But Barry Pollard from Google, who helps manage the core web vitals project did say back on July 8th on Bluesky:
We've noticed another dip on the metrics this month, particularly on mobile. We are actively investigating this and have a potential reason and fix rolling out to reverse this temporary dip. We'll update further next month. Other than that, there are no further announcements this month.
I should add, the dip seems to be on desktop, not just mobile, for most sites - from what I can see.
Here is one screenshot:
Here is Rafael Rubio's screenshot:
Rafael Rubio wrote, "is there a known issue or bug with Core Web Vitals reporting in Search Console? Seeing a sudden massive drop in reported URLs (both “good” and “needs improvement”) on mobile as of July 12."
It seems pretty widespread, so it might be some sort of Core Web Vitals update? Do you see it?
We see something similar in our properties, and the unusual behavior is that the good and those that need improvements decline, but the poor ones do not improve -looks like a glitch for sue
— Juan C Vargas (@juancvargas) July 15, 2025
John Mueller from Google did respond on Bluesky but he didn't seem to address the more global issue around this? He wrote, "These reports are based on samples of what we know for your site, and sometimes the overall sample size for a site changes. That's not indicative of a problem. I'd focus on the samples with issues (in your case it looks fine), rather than the absolute counts." When quesitoned about it happening to many other sites, John added, "That can happen. The web is dynamic and alive - our systems have to readjust these samples over time."
Even Jamie Indigo asked John to confirm, she asked, "It seems like ... everyone beyond the usual ebb and flow. Confirming nothing in the mechanics have changed?" And John replied, "Correct, nothing in the mechanics changed (at least with regards to Search Console -- I'm also not aware of anything on the Chrome / CrUX side, but I'm not as involved there)."
John later added, "The sampling fluctuations apply to the structured data reports, AMP, CWV, HTTPS, and I think backlinks - I assume that's just what you're seeing there."
Here is Barry Pollard's post on Bluesky:
We've noticed another dip on the metrics this month, particularly on mobile. We are actively investigating this and have a potential reason and fix rolling out to reverse this temporary dip. We'll update further next month. Other than that, there are no further announcements this month.
🧵 3/3 🏁 FIN
— Barry Pollard (@tunetheweb.com) July 8, 2025 at 5:28 AM
I should note, the change is interesting but don't worry about this for your search rankings.
Finally, core web vitals has no relation at all to Google core updates.
Forum discussion at X.
Update: Barry Pollard from Google added more on Bluesky, explaining his other reply was maybe unrelated to this. He said:
There's potentially two different things going on here.First up, on the Chrome side, we are investigating some Core Web Vitals regression in the last month, particularly on Android. That's in the realm of a few percentage points dip, so not massive, and suspect only the most diligent web performance nerds would have even noticed this without my highlighting it, but it is something we on the Chrome side keep an eye on and like to give an eco-system update on our monthly CrUX BogQuery releases.
The GSC graphs in Barry Schwartz's post do NOT appear to me to show Core Web Vitals regressing, but instead a drop in the number of URLs with eligible Core Web Vitals. A subtle difference, but an important one.
My reading of those graphs are that the same percentage of URLs are passing or failing but for some reason there are just less overall URLs showing in the graph. I don't know why as this is managed by the Search team and that's kept quite separate from the Chrome team . I also not sure I agree with the article saying the number of poor URLs hasn't dropped. In all those screenshots the number of poor URLs is zero so of course they haven't dropped!
Anyway, that's not to say the issues aren't related, and I agree the timing is suspicious, but I'm also seeing the same on Desktop GSC graphs, and on the Chrome side we're not aware of (nor seeing!) any regression there. So I suspect two separate issues.
This story was first posted at 5:30 am but was then updated at 7:30 am.
