In April, Google updated how the Cumulative Layout Shift (CLS) metric in major web vitals was calculated. In short, Google has made the metric more beneficial for most sites, so your CLS scores may increase on their own on June 1 in Google Search Console reports.
On June 1, Google job “CLS metrics have been updated to reflect a more accurate representation of on-page layout changes. You might see changes in your page’s CLS statuses (mostly positive) reflecting this change.” This is after Google posted the exact same message on April 13.
But I’ve confirmed with Google that means Google noted the change that happened in April, but the scores themselves weren’t reflected in Search Console until June 1st.
Google’s Jeffery Jose said the Twitter “The June 1 changes reflect the updated CLS definition, as described in the post https://web.dev/evolving-cls/. It took a few weeks of work to push the update from CrUX to SC .”
The June 1 changes reflect the updated CLS definition, as described in the https://t.co/FKr2xiuzhj Publish. It took a few weeks of work to get the update from CrUX to SC.
— Jeffrey Jose (@jeffjose) June 1, 2021
So you should see improvements in your CLS scores without doing anything.
So check your Web Vitals baseline report in Google Search Console and expect more green bars from the CLS metric:
Update: Here’s an extreme example of what makes a huge difference to a site:
Google’s new CLS metrics are now available in Google Search Console. You may notice a few improvements, like the screenshot below. The client has worked hard over the past few months and moved many “bad” to “needs improvement”, and now to “good” https://t.co/Wn4RXrrIPA via @rustybrick pic.twitter.com/0enOEE5w1T
—Glenn Gabe (@glenngabe) June 2, 2021
Discussion forum on Twitter.
Update: On June 7, Google changed the wording to read “CLS metrics have been updated to reflect a more accurate representation of layout changes on the page. The CLS metric now has a maximum session window with an interval of 1 second, capped at 5 seconds as detailed in the post here. You might see changes in your page’s CLS statuses (mostly positive) reflecting this change.”