This audit measures the amount of blocking time attributable to ad-related scripts. This captures time where the JS thread is blocked by an ad-related script for long enough to be noticeable by users as it can directly affect input delay or content loading.
The most important factor in ad JS blocking time is how many ads are being loaded at once. Our recommendations are:
- Load fewer ads at once or reduce ad density, if feasible
- Lazy load ads below the fold
- Reduce batch sizes if using Single Request Architecture (SRA) in GPT.
To learn how blocking time is defined, see this article on Total Blocking Time
A script is considered to be ad-related if it is either an ad tag or labeled as an "ad" script by Third Party Web.