Will customers wait for it?
Content stays still while the page loads
We check this as: Cumulative layout shift (median of 3)
Why it matters
Cumulative layout shift measures how much the page jumps around as it finishes loading, like a button shifting right as you go to tap it. It is one of the most annoying things a website can do to a visitor on their phone.
How we deliver it
We measure this directly, the median of three real page loads, and reserve space for images and content up front, so nothing jumps.