Layout Shift Debugger

Visually simulate Cumulative Layout Shift (CLS)

Estimated CLS Score
0.000
Good

Elements

Simulation

Inspector

Select an element to inspect

Viewport View (Fixed 800x600 for calc)

CLS Best Practices

  • Always include width and height size attributes on your images and video elements.
  • Never insert content above existing content, except in response to a user interaction.
  • Prefer transform animations to animations of properties that trigger layout changes.
  • Reserve space for ad elements and dynamically injected content.