Fix Web Vitals (CLS, LCP, TTI) to improve SEO and performance.


Well-known member
Google believes that the Core Web Vitals are critical to all web experiences.

Please see this report:
You can run this for yourself here:
I used this xenforo URL to test:

Google has added Web Vitals as signals to their search console. A lot of webmasters seem to have a lot of poor or bad ranking pages for the following web vitals metrics:
Largest Contentful Paint
Cumulative Layout Shift
More information on these metrics here:

This often concerns threads and media.
Time to interactive and speed index also seem to be an issue.
Please look into this to improve our site performances.

Everyone can look up your Google Search Console Report here:
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Upvote 81


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After a year that I was going crazy for this, it seems I have fixed all the CLS problems.
I have also seen that in the last version of Xenforo the developers seems to have solved the problem with the default theme, but in my one (not the default oe) still I had it.
So try to check these things:
On mobile it seems that the "Quick Thread" option, was the one that create Layout shift, so with this useful addon of @Ozzy47 I have solved the problem:
Disable the function for guest in the Group Permissions.

About the desktop version is the explicit size of the logo that must be added in the code as you can see here:
I have not used these solutions because I don't know the code (make some tests but without success) and the addon proposed make disappear many ads on my site so I have removed it, but the problem is that related to logo size and I have fixed it by the setting panels of my theme.

Also as Briansol says some minor CLS issues are realted to the ads that need to have explicit size in the code generated from the ads, I have just asked to Siropu days ago if was possible to fix this problem in him optimum plugin and him says that is working on it to release a fix in the next release.

Use or to check and not Pagespeed because this give too much false negative.

As additional check if you still have CLS problem look also Lazyload plugin if you use it, trying to disable it and see if it solve the problem, if yes try to set the right configuration to avoid the shifts.

@Mouth in our case (cause we use the same theme) go to "[Nulumia] Header & Navigation" and set the right size of the logo you are using, in this panel.

Hope this can be helpful also for you


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In each way those I have mentioned are problems there were on my site and each site have the own ones. I have wrote my ones that maybe could help someone.
In each way to understand what are the CLS problems involved of each site is important to check the voice in Pagespeed or "Avoid Layout shift" and start from there.
After that I'm totally agree that the (CLS, LCP, TTI) should be improved to get a better performance and so better ranking values for the contents.


Well-known member Thread result (for this very thread):


The results for this very thread:
Measure.png is a website that AFAIK does not run any 3rd party addons. Those sites that do will find that pages load a lot of unused and queries, JS, CSS from addons that are not even needed on the page.

If XF would split this up and allow us to turn off, then this would speed up pages significantly and improve Web Vitals score.


Well-known member
Every little thing impact to the ranking of a site.
Good contents is the first thing, all the rest of the optimizations come immediately after.
Core Web Vitals is really important for the best user experience, that impact to the contents and site quality.

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