Google's CLS (Cumulative Layout Shift) indicator measures how often these changes occur. The higher the indicator, the more unstable the layout. When this indicator is 0, no unexpected movement of the page content has been detected. Read more about this CLS indicator and how it is calculated in the Google documentation.
Layout stability is important because it is taken into account by Google in its ranking criteria and most importantly, because it negatively impacts the user experience when browsing the page. Faced with an unstable page, the user may be frustrated by the loss of visual cues and worse, he may think that the site does not work because of a shift during interaction on buttons that move for example.
In order to provide an optimal experience for your users, it is necessary to keep the CLS indicator below 0.1.
Here you have a few tips to keep the indicator below the critical bar :