Skip to main content
Checks for Cumulative Layout Shift prevention
Rule IDperf/cls-hints
CategoryPerformance
ScopePer-page
Severitywarning
Weight6/10

​
Solution

CLS measures visual stability - how much content shifts during load. Prevent layout shifts by: 1) Always set width and height attributes on images and iframes. 2) Reserve space for ads and embeds with CSS min-height. 3) Use CSS aspect-ratio for responsive media. 4) Avoid inserting content above existing content. 5) Use transform animations instead of properties that trigger layout.

​
Enable / Disable

​
Disable this rule

squirrel.toml
[rules]
disable = ["perf/cls-hints"]

​
Disable all Performance rules

squirrel.toml
[rules]
disable = ["perf/*"]

​
Enable only this rule

squirrel.toml
[rules]
enable = ["perf/cls-hints"]
disable = ["*"]