Understanding Cumulative Layout Shift (CLS)
CLS measures visual stability by tracking unexpected layout shifts. A good CLS score is below 0.1.
- Watch the multiple images load without dimensions
- Notice how content keeps shifting as elements load
- Open DevTools (F12) → Performance tab
- Click the reload button (⭮) to record and observe the severe layout shifts
This text will shift repeatedly!
More shifting text...
Even more shifting text!
How to Fix CLS:
- Always specify image dimensions
- Reserve space for dynamic content
- Avoid inserting content above existing content