Glossary · C
Cumulative Layout Shift
Cumulative Layout Shift measures how much visible content moves unexpectedly during a page’s life, such as text jumping when an image or advertisement loads above it.
Extended definition
In more detail.
CLS is scored from the size and distance of unexpected shifts; a good experience is 0.1 or less. Images without declared dimensions, late-loading fonts, injected banners and advertisements are the common causes. The fixes are structural: reserve space for every element, declare image dimensions, load fonts predictably and avoid inserting content above what the visitor is reading.
In our work
Where it appears.
Declared image dimensions and reserved space are part of the design system we build. See identity and design system.
By David Selakovic · Published 2026-10-16 · Revised 2026-10-16 · Reviewed every 180 days