Tag Master – GTM & GA4 Debugger, DataLayer Inspector

Debug GTM, GA4, dataLayer, Meta: 52 platforms in one side panel. Consent Mode V2 audit, server-side GTM, test modes. Local only.

Stop juggling GTM Preview, DebugView and the console. Tag Master shows every tag, every dataLayer push and every tracking hit in one side panel — decoded, validated and consent-checked. WHAT YOU ACTUALLY SEE Every tracking request is decoded into named parameters instead of a query string: the account it reported to, the event it carried, the value and the currency. Each request is tied to the dataLayer push that caused it, so "did that click send anything, and what" is answerable at a glance. Coverage spans 52 analytics and advertising platforms and needs no configuration — whatever the page uses is recognised on sight. SERVER-SIDE TAGGING Hits routed through your own first-party endpoint are still recognised and labelled, including collect calls on your own domain, first-party loaders and the cookies that go with them. Half-finished migrations are named as such rather than quietly passing. CONSENT MODE V2, READ AS A SEQUENCE Consent is an order of events, not a setting: the defaults have to be in place before the tags load, and the visitor's answer has to reach them. Tag Master reads that order out of the page and reports every vendor that kept firing while advertising consent was denied. CONVERSIONS, COMPARED The same purchase side by side across every platform that reported it — values that disagree, a value sent without a currency, one conversion counted twice, and platforms that were active on the page but stayed silent. BUILD THE GTM SETUP FROM A REAL EVENT Press Pick Event, then do the thing on the page. The push it produces is taken apart for you: tick the values you want and you get the Custom Event trigger and the Data Layer Variable names to match. One click often produces several pushes, so the alternatives are offered beside it. Walk a whole funnel, keep each step, and export the lot as one container file to import into GTM. A CONTAINER INJECTOR THAT STILL WORKS Inject a container into any page, persistently per site if you want — the feature most debuggers lost in the Manifest V3 migration. ALSO IN THE PANEL • The stack a page is built on: e-commerce platform, consent tool, frameworks • A one-click audit of the whole session, exported as a Markdown report you can paste into a ticket • Cookie inspector, CSP compatibility check, HAR / JSON / CSV export • Per-platform test modes, and the option to silence one vendor's hits while you test • No account, no login, no telemetry — everything stays in your browser