Cumulative Layout Shift (CLS)
The Cumulative Layout Shift (CLS) is a Core Web Vitals metric measuring the sum of all individual layout shift scores for every unexpected shift that occurs during the entire lifespan of the page.
The score starts at 0 for fully static pages and growing as the number of shifts found. The lower the score the more stable the layouts are.
Good: 0 - 0.1
Needs Improvement: 0.1-0.25
Poor: above 0.25
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Core Web Vitals