Omnibug is a long-standing open-source decoder that lists tracking requests in a DevTools panel, covering roughly 69 providers. It matches requests by hostname, so traffic sent through a first-party or server-side endpoint does not look like the vendor it belongs to.
Only in Tag Master
Only in Omnibug
None in this comparison.
Both
| Capability | Tag Master | Omnibug |
|---|---|---|
| What it sees | ||
| Platforms decoded | 71 | ~69 |
| Server-side GTM hits recognised | ✓ | – |
| Works on first-party endpoints | ✓ | – |
| How deep it goes | ||
| Explains why a GTM trigger fired | – | – |
| dataLayer monitor | ✓ | – |
| Consent Mode V2 state | ✓ | – |
| Flags vendors firing without consent | ✓ | – |
| What you can do with it | ||
| Block a vendor’s hits | ✓ | – |
| Force GA4 DebugView | ✓ | – |
| Inject a GTM container | ✓ | – |
| Element picker to GTM trigger | ✓ | – |
| Export captured hits | ✓ | ✓ |
| Practicalities | ||
| Interface | Side panel | DevTools panel |
| Last updated | Sep 2026 · v1.9.0 | Jan 2025 |
| Price | Free | Free |
Omnibug was compared in August 2026 from its public documentation and Chrome Web Store listing; the Tag Master column is current as of version 1.9.0. Something out of date? Tell us and we’ll fix it.
A different long tail: roughly 69 providers to our 71, and about twenty of them are ones Tag Master does not read — Ensighten, Webtrends, Dynamic Yield, Invoca, Teads and Seznam Sklik among them. If your list leans that way and you do not need server-side or consent auditing, it may cover more of it. It is also open source, which Tag Master is not.
For most debugging, yes. In this comparison Tag Master does 9 things Omnibug does not — server-side GTM hits recognised and works on first-party endpoints among them. Omnibug still has its place, and the section on when to use it says so plainly.
Yes. They read the same requests from different places — Omnibug in DevTools, Tag Master in the side panel — and nothing stops both being installed.
Yes — every feature, with no account and no paid tier, including for commercial work.
All five tools in one table: the full comparison. Other comparisons: Tag Assistant · Meta Pixel Helper · Analytics Debugger
Tag Master is free, needs no account, and collects no data.
Add to Chrome — Free