🔍62 platforms · one side panel

The GTM and GA4 debugger for every tag,
not just Google's

Tag Master decodes GA4, GTM, Google Ads, Meta, TikTok, Adform, Adobe and 45 more platforms in real time — then tells you what each one got wrong, and switches on that platform’s own test mode when you need it.

Add to Chrome — Free ☕Buy me a coffee

No account, no login Zero data collection Works on sites you do not own

Tracking requests live

POSTsst.yoursite.com/g/collect?v=2

enpurchase

tidG-8QK2LM

cuUSD

epn.value149.90

gcsG100

sGTM no consentRouted through your own domain — still decoded, and gcs=G100 means ad consent was denied.

One panel instead of five tools

Everything you normally check across GTM Preview, DebugView, the console and three vendor helpers

dataLayer push to hit, linked

Every dataLayer push lists the requests it produced, matched by event name across platform spellings. Then it puts what the push carried next to what the tag actually sent.

✓ Push vs hit comparison
✓ Holds up through GA4’s batched hits
✓ Turns a push into a GTM trigger recipe

The whole journey, not one page

A funnel checklist across the pages actually walked, a client ID that changes mid-journey, domain hops with no linker, and the chain from ad click to conversion.

✓ Client ID and session continuity
✓ gclid → linker cookie → conversion
✓ Shareable Markdown report

Network inspector, 62 platforms

Every hit decoded into readable parameters — account ID, event name, value, currency — not raw query strings.

✓ Enhanced Conversions SHA-256 check
✓ Meta CAPI deduplication flag
✓ HAR, JSON and CSV export

Server-side GTM, seen

Hits proxied through your own first-party endpoint are still recognised, labelled and decoded. Paste your preview token and they appear in your sGTM session.

✓ Path-first matching, host-agnostic
✓ X-Gtm-Server-Preview header
✓ First-party cookie detection

Consent Mode V2 audit

Live state for all four signals, plus a red flag listing every vendor that kept firing while ad consent was denied.

✓ gcs and gcd decoding per hit
✓ Default vs update distinction
✓ Violation report in one click

Every platform’s test mode

Google has Tag Assistant and DebugView. TikTok, Snap, Microsoft UET, Tealium, Criteo, Yandex, Hotjar and Adobe Launch each have their own — switch one on and its test tool starts receiving your events.

✓ 8 platform debug modes
✓ GA4 DebugView + sGTM preview
✓ Per-vendor hit blocking

GTM injector that still works

Drop any container onto any site, persisting across reloads, then open Tag Assistant ready to connect. Snippets are saved per container — paste once, reuse forever.

✓ Manifest V3 compatible
✓ Survives page reloads
✓ Saved snippet library

Visual trigger builder

Click any element and get a ready-to-paste GTM recipe: stable selector, condition options with copy buttons, and a variable that extracts prices automatically.

✓ Climbs to the clickable parent
✓ Skips unstable utility classes
✓ dataLayer monitor with GA4 schema checks

How it compares

Every tool here is free. The difference is coverage.

Swipe the table to see the other tools

Capability	Tag Master	Tag Assistant	Omnibug	Meta Pixel Helper	Analytics Debugger
Platforms decoded	62	Google only	~69	Meta only	GA4, GTM, Adobe +
Server-side GTM hits recognised	✓	–	–	–	–
Explains why a GTM trigger fired	–	✓	–	–	–
Flags vendors firing without consent	✓	–	–	–	–
Element picker to GTM trigger	✓	–	–	–	–

See the full comparison

Questions

Is Tag Master free?

Yes — every feature, with no account, no login and no paid tier. The extension collects no data; captured sessions stay in your browser.

How is it different from Google Tag Assistant?

Tag Assistant covers Google tags only and runs its debug session from an external site. Tag Master decodes 62 platforms in the side panel next to the page — including Meta, TikTok, LinkedIn, Adform, Criteo and Adobe Analytics — and adds server-side GTM detection plus Consent Mode V2 auditing. The two work well together: Tag Master can open Tag Assistant for you with the container prefilled.

Can it debug server-side GTM?

Yes. Hits are matched by request path rather than hostname, so GA4 requests proxied through your own first-party endpoint are still recognised and marked. You can also paste your X-Gtm-Server-Preview token so requests from your browser appear inside your server container preview session.

Does it collect any data?

No. There is no account, no telemetry and no external server. Everything is processed and stored locally.

Will blocking hits break the site I am testing?

Blocking only affects tracking requests for the vendors you tick, and only while the toggle is on. The site own functionality is untouched, and blocked hits are still listed so you can see what would have been sent.

The GTM and GA4 debugger for every tag,
not just Google's