Over the past week or so, there has been a lot of chatter in the SEO industry around the potential threat third-party browser extensions can have on your core web vitals scores. Specifically how it might impact your rankings in Google Search based on how a user who visited your site may have installed a plugin that impacts maybe the CLS score on your pages.
The truth is, this is not really a huge concern for a few reasons:
(1) Most people do not have browser extensions on their mobile browsers and these scores, at least how Google uses them for ranking, are mobile only. John Mueller from Google reiterated this point on this concern on Reddit when this topic came up, John said "Yeah, page experience is currently slated only for mobile search, and if lots of people have figured out how to install plugins on chrome on Android, I'd love to know the trick."
(2) Most users, and no, SEOs are not the average browser user, probably do not install browser extensions on their desktop browser (not that it impacts Google anyway).
(3) The Page Experience Update won't be a massive ranking change anyway.
This came up when Dave Sottimano tweeted and Addy Osmani from Google responded:
I would group this question into the same category as “what if I game the CWV metrics?”. (1) Users are not going to see benefits - if investing that effort in messing, why not just improve the experience? (2) If we had anti-spam or anti-gaming mechanisms in place, it’s a bit moot
— Addy Osmani (@addyosmani) March 10, 2021
Here are the hat tips:
Makes complete sense, but might shock some people :) -> Google Confirms That Third-party Browser Extensions That Users Have Installed Will Impact Core Web Vitals Scores. "Real-world user experience is just that..." https://t.co/AlbraNwTXi via @tldrMarketing h/t @dsottimano pic.twitter.com/FLxBZMniV9
— Glenn Gabe (@glenngabe) March 11, 2021
In any event - nothing to worry about - in my opinion.