One of the items in the core web vitals, which is part of the upcoming Google Page Experience Update, is Cumulative Layout Shift (CLS). There have been some reports that cookie consent banners have been impacting a site’s Cumulative Layout Shift score. Google wants examples of this, so share when with Google’s Martin Splitt on Twitter.

Martin Splitt wrote “So I’ve been asked a few times “What about CLS [Cumulative Layout Shift – one of the Core Web Vitals metrics] and cookie consent banners?” and I have looked at a few sites and libraries to implement those…. and have seen performance impact, but not really impact on CLS. So if you’re seeing cookie consent banners that impact CLS, answer here and I’ll take a look. But anyway – there are already solutions that have zero impact on CLS.”

What are cookie consent banners? You know, the banners you see for you to say sure, I am cool with you using cookies on your web site. They look like this:

We do not want these cookie consent banners to cause a negative CLS score, so if you have an example, share them with Martin Splitt on Twitter.

Forum discussion at Twitter.