HTML5 ad performance preflight
Check Heavy Ad Intervention risk in HTML5 creatives
Heavy Ad Intervention can unload an ad that consumes too much CPU or network bandwidth. Deep Audit measures the signals that help teams find expensive creatives before they reach production.
The short version
The ad looks fine on a developer workstation but is unloaded or behaves inconsistently on a lower-powered device or constrained connection.
What Ad-Preflight checks
- ✓Main-thread time and long tasks during creative execution
- ✓Network requests and download activity
- ✓Runtime behavior under CPU throttling
- ✓Visual and animation behavior at each ad size
What it cannot guarantee
- !Chrome adds privacy-related variability to intervention thresholds
- !The measurement is a risk signal, not a deterministic promise of intervention
- !Publisher wrappers and descendant frames can change the final serving behavior
Run it in the desktop app or CLI
Designers and AdOps can drop a campaign folder into the desktop app and follow the visual report. If you work in a terminal or CI pipeline, the same checks are available through the CLI.
- 1.Run Deep Audit on each size rather than relying on a static ZIP size.
- 2.Review CPU and network findings in the report.
- 3.Reduce expensive loops, oversized resources, and unnecessary requests.
- 4.Re-run under the same audit conditions before handoff.
CLI equivalent
npx @ad-preflight/cli package ./my-ad --fixPlatform reference: Chrome for Developers: handling Heavy Ad Interventions