Performance check
The page does not shift while it loads
Cumulative Layout Shift on a throttled mobile profile.
medium severityperf.cls
Run this check on your site
Runs just this check in quick mode. The report opens with the evidence and the fix.
Why it matters
Content that jumps after it appears is the most common complaint about a slow feeling website. A stable layout reads as a faster one.
How to fix it
Reserve the space for images, ads and embeds with explicit width and height, and avoid inserting content above what is already on screen.
The details
- Category
- Performance
- Severity of a failure
- medium
- Confidence
- medium
- Needs a browser
- Yes
- Check id
- perf.cls