GTM audit

A container that passes every preview check can still be teaching Google the wrong thing. Preview mode answers whether a tag fires. It does not answer whether it should, whether something else already fired for the same event, or whether the value it carries means what the name on it says.

What we need from you

Viewer access to the GA4 property, and read access to the Google Tag Manager container. That pair is the most routinely granted in the industry: no admin rights, no second factor, no developer, and nothing on your site changes while we look. You can revoke both the day the read is finished.

What comes back

Tags, triggers, variables and the server-side container, read against what somebody meant to count — because a conversion event is never wrong on its own. It is wrong against a specification, and usually nobody wrote one. So we establish that first, and check against it after.

Each finding carries which tag, which trigger and which number it moves, and is labelled with how much it can bear: a specification violation holds up against a hostile reader, and a judgement about setup is marked as a judgement rather than borrowing the weight of the first kind.

What it cannot tell you

80 to 90 percent is the realistic ceiling on measurement accuracy, and nobody clears it. Consent refusals, blockers and people moving between devices take the rest. So what this produces is a known state rather than clean data. You will not get a perfect number out of it. You will get to know which of your numbers can carry a decision and which cannot — and today that is written down nowhere.

What if my agency built it?

Then most of what we find was probably chosen. A setting is not a fault until somebody has asked whether it was deliberate, so we ask before calling anything wrong — and the answer often closes the question with nobody having been wrong. What is left is a list your agency can work from, in their own vocabulary, with the evidence attached.

Where this sits

A GTM audit reads the layer between your site and every platform that decides on it. It is the measurement half of one level of a longer ladder: what your company tells Google and Meta about itself, and what those platforms then decide on the strength of it. Most companies stop here, and stopping here is a reasonable thing to do.

Tell us what you are trying to fix. That is the whole first step.