CATEGORY · Performance · B02
CLS (Cumulative Layout Shift)
CLS measures unexpected layout shifts during a visit. A value of 0.1 or less at the 75th percentile meets the good threshold.
Full definition
CLS measures unexpected layout shifts during a visit. A value of 0.1 or less at the 75th percentile meets the good threshold.
Concrete Shopify example
Illustrative example: a promotional badge appears above the buy button and shifts the product page. Reserving space can prevent that shift.
My take
Inspect scrolling and interactions as well as loading. Check media dimensions and late-injected content.
Related terms
Go further
Sources and editorial context
Teo Comyn · Updated
Technical references consulted for this revision. Illustrative examples are not measured client results. Check the current documentation and your store before applying a change.
Editorial policy