Free tool
Tag Explorer every tag, one tree
Discover every GTM container, analytics, advertising and tracking tag on any page, laid out as an interactive tree with duplicates, dead tags and setup oddities called out.
We fetch the page's initial HTML, find every GTM container, read each container's published configuration and lay the whole lot out as a tree, with duplicates and dead tags flagged.
Attention and recommendations
Issues and clean-up tips for this page, separate from the tags listed above.
New to these tags? Read the Tag Guide: plain-English explainers for every tag type. This is a server-side scan of the initial HTML plus each GTM container's published config. Tags that load only after consent or JavaScript hydration may not appear; accept consent on the page, then re-scan.
How it works
How Tag Explorer works
You give it a page address. Our server fetches that page exactly once, reads the HTML the site sends before any JavaScript runs, and looks for Google Tag Manager loaders in their real loader context (the gtm.js bootstrap or the noscript iframe). For each container found it downloads the published container file from Google and reads the tag list inside: GA4, Google Ads, Floodlight, Meta, TikTok, LinkedIn, Clarity, Hotjar and around fifty more are recognised by name, and Custom HTML tags are inspected for the pixel they carry.
Tags hardcoded straight into the page are listed in a second trunk. The tool then compares everything: the same ID in two places is a duplicate, one vendor with two IDs is split tracking, a Universal Analytics or Google Optimize tag is dead, and an empty or one-tag container is worth a second look.
Reading the result
- Each card shows the tracking ID in monospace when we have one, the vendor and category underneath, and an i button that opens a plain-English note with a link to the Tag Guide.
- Copy tree gives you the structure as text for a ticket or an email. Copy for AI gives a compact digest with a HEALTH line and a NEXT action, written to be pasted into an assistant.
- The HTTP badge is the status the target site gave our scanner. Sites behind a bot challenge answer 403 or 503 and show nothing, which is a fact about the site, not a bug in your tags.
Tag Explorer questions
What does Tag Explorer actually scan?
It fetches the page the way a browser would on first load and reads the HTML the server sends. From that it finds every Google Tag Manager loader, then fetches each container’s published configuration from Google and lists the tags inside it. Hardcoded pixels on the page itself are listed separately under "Directly on page".
Why does a tag I know is firing not show up?
Tags injected after consent, after a JavaScript framework hydrates, or by another tag at runtime are not in the initial HTML, so a server-side read cannot see them. Accept consent on the site, then re-scan, or check the Network panel in your browser for the live picture.
What counts as a duplicate?
The same tracking ID loaded from two independent places: for example a GA4 measurement ID in a GTM container and the same ID hardcoded in the page, or across two containers. That double-counts data and loads the vendor script twice. Different IDs for one vendor are flagged more gently as split tracking.
Can a script or an AI agent use this?
Yes. GET /api/tools/tag-explorer?url=https://example.com returns the full JSON, and adding format=agent returns a compact plain-text digest written for pasting into ChatGPT, Claude or a terminal. There is a soft limit of 40 scans per 10 minutes per IP.
Does it change anything on the site I scan?
No. It only reads public HTML and Google’s public container files. Nothing is logged in, nothing is submitted, and we keep results for three minutes only so repeat scans are quick.
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