CLS
Cumulative Layout Shift measures how much visible content moves unexpectedly during page load.
Why it matters
On a marketing site the three usual causes are the sticky call to action, the cookie banner and web font swap.
How it is measured
Run Lighthouse and read cumulative-layout-shift. Under 0.1 is the target.
Checks that involve cls
Related terms
Questions
What is cls?
Cumulative Layout Shift measures how much visible content moves unexpectedly during page load.
Why does cls matter?
On a marketing site the three usual causes are the sticky call to action, the cookie banner and web font swap.
How is cls measured?
Run Lighthouse and read cumulative-layout-shift. Under 0.1 is the target.