The mistake: ad slots that shove content down

The mistake: ad slots that shove content down

Ads are a sneaky CLS — Cumulative Layout Shift — offender. When an ad loads, it suddenly appears and pushes your article down, right as someone starts reading. The score climbs and readers lose their place.

Think of it like a guest arriving late to a packed bench: everyone has to scoot over to make room.

How to fix it:
— Give every ad container a fixed min-height in your CSS, matching the ad's size.
— Reserve that space before the ad loads, so the box is already waiting.
— For responsive ads, set the height for the largest size it might use.

Now the ad fills a spot that was always there, and nothing jumps.

Try this: scroll your page slowly on a phone. Anywhere content leaps, reserve space for whatever loaded there.