This Core Web Vitals nonsense - fluctuating reports

[MrOnTheRopes]

So one day I have just 'green' good pages showing and then all of a sudden it starts to flip the other way - all bad with CLS issues.
The pages didn't change at all.

So I just tell it to validate fix and after a while they back to good again.
And then not long after they're bad again (always CLS issues).

Is it even worth getting bothered about? Seems completely random to me if the report changes so much for pages that aren't even changing.

[Dimitri]

Your pages are not changing, but do they call third party codes ? ... Like ads? Third party ads can cause CLS, if you are not using fixed sized containers. This is just one example, among many, when relying to third party codes.

[MrOnTheRopes]

Thanks for the pointer, Dimitri :)

We don't have any 3rd party ads. Looking at the source for one of the affected pages the only 3rd party stuff I can see is FB pixel code and GA. Could the FB pixel stuff maybe cause it? I don't actually use the FB tracking anyway so could chop that out.

[tangor]

A general rule of thumb is to use as few third party as possible. Just keeps things simple and reduces the avenues were oddities might happen.

[robzilla]

Your reference to "validate fix" means you're probably looking at the Core Web Vitals reports in the Search Console.

Hover over the question mark next to the "Validate fix" button and you'll read this:

"Verifying a fix for an issue means that Google must monitor usage statistics for up to 28 days to ensure that the issue is fixed. In some cases we can verify the fix in less time. The fix verification window begins when you start tracking for your fix. If not enough users visit your page, we might not be able to verify the fix."

You can read more about the validation process here [support.google.com]. In short, Google does not send Googlebot to measure your vitals, but depends on the data flowing in from Chrome users.

If you haven't actually fixed anything, obviously there's no point in trying to validate that.

Your CWV reports will fluctuate because the field data fluctuates.

[MrOnTheRopes]

I missed that so didn't know that's how it worked. Thanks, robzilla :)
I just got super angry when I posted this thread yesterday haha

[MrOnTheRopes]

Completely fine and then just flip again. All 'good' pages suddenly become 'bad' pages (due to sodding CLS which no actual users notice or care about). They're just pages that appear with no adverts/popups/whatever. Just pages that appear.

Absolutely no changes to the pages between being good and bad.

The solution seems to be stop looking at that silly report.

[robzilla]

They may "just appear" for you, but that doesn't mean your users have the same experience. Webmasters tend to have above-average hardware and a high-speed internet connection, and often choose hosting that's geographically close to them. If you're in the US, and your hosting is, too, but many of your users are from Europe or Asia, you can bet their experience will be different from yours. Don't assume it works great for everybody when it does for you.

Many webmasters seem to think that because they haven't made any changes to their pages, that Core Web Vitals cannot change. In fact, the field data that the CWV scores are based on changes constantly, regardless of what you're doing to your site. It's real people using real devices with real network conditions, and none of those are stable or predictable.

If you keep flipping between "good"/"bad", it's possible you're always on the bad side of "good" or the good side of "bad" and small differences in the field data have you crossing over from one to the other. In other words, when you're "good" there may still be room for improvement. Google also sometimes makes adjustments to the classification of the vitals.

Of course, not looking at the report is also a solution, because it doesn't really matter all that much in terms of search rankings.