Free tool
GTM Container Auditor
Export your container, drop it here, get a graded report. No Google login, no OAuth — the export is analyzed in memory and only the report is kept.
How to export
- In Tag Manager open the container → Admin → Export Container.
- Pick the live version to audit what visitors get, or the workspace to audit unpublished work.
- Download the JSON and upload it above.
What it checks
- Duplicate Google tags
Two config tags for one measurement ID — the container-side cause of doubled page_views.
- Tags that never fire
Active tags with no trigger, and references to variables that don't exist.
- Orphans
Triggers attached to nothing, variables referenced by nothing.
- Consent readiness
Non-Google tags with no Additional Consent Checks, so the CMP can't gate them.
- Custom HTML risk
document.write, eval(), innerHTML, and scripts loaded over plain http.
- Hygiene
Hardcoded IDs that should be constants, naming-convention conformance, paused-tag bloat, All Pages overload.