Cumulative Layout Shift (mobile lab)

What to fix

Stabilize mobile layout shift by reserving space for images, embeds, and late banners.

Step-by-step fix

1. Add width and height (or CSS aspect-ratio) on content images and iframes in the scanned template.
2. Reserve space for cookie/consent banners and sticky headers so they do not push content after first paint — configure the CMP or theme sticky bar with a fixed height.
3. Load webfonts with a fallback size close to the final face to avoid text reflow, or subset the font.
4. Avoid injecting ads or related-posts blocks above existing content without a reserved slot.

Choose the path for your setup

• Cookie banner plugins

  Prefer a banner that overlays without expanding the document flow, or reserve a top slot matching the banner height.

Confirm it is fixed

Re-scan and compare mobile CLS (A-cls). Lab CLS should drop when reserved space matches the late-loading UI.