Tagstack audits any public Google Tag Manager container, estimates martech cost and exports JSON. Free plan, paid from €19/month. Read the review.
Researched and fact-checked by Bartu Cavusoglu · Updated October 26, 2026
Tagstack is a web-based scanner for Google Tag Manager (GTM) containers. A user pastes a website URL or a container ID, and the tool reads the public container, grades the setup and shows every tag, trigger and variable it contains. The first scan needs no signup and no access to the container.
The product is positioned for people who work with tracking stacks: analytics professionals who audit and repair setups, agencies that qualify leads and deliver reports, and martech sales teams that want to know which technologies are running on real sites. The company says its index covers more than 3 million scanned containers and over 50,000 identified technologies.
Tagstack relies on the fact that an active GTM container is publicly served at its Google URL. The tool fetches and decodes that container, then turns the raw contents into a structured, readable report. This is why scanning needs no account access and works on a competitor's site as well as your own.
The report includes a container health grade, a ranked list of issues sorted by impact, and a full inventory of tags, triggers and variables. It also checks areas such as consent mode, server-side tagging, the consent management platform, naming and performance. Each scan adds an estimate of what the detected stack costs per year.
Results can be saved as snapshots, shared by public link, or pulled through the API and MCP server.
The audit is the core feature. It produces a health score and a prioritized issue list, replacing the manual tag-by-tag review inside the GTM interface. The martech cost estimate lists detected tools by category and yearly cost, which helps identify redundant software on your own site or size a prospect's budget.
Container export converts a scanned container into a JSON file that can be reimported into GTM, including tags, triggers and variables. Saved scans keep a snapshot of a container at audit time and build a history showing how the setup changes, and each saved scan has a public URL that needs no account to view.
For automation, the API returns scan results and technology lists, and the MCP server brings the same data into Claude, ChatGPT and other assistants.
Tagstack is a web tool that inspects Google Tag Manager containers. It reads a public container from a URL or container ID, grades the setup and lists every tag, trigger and variable.
Tagstack has a free plan at €0 and a Starter plan at €19 per month, excluding applicable taxes. Enterprise pricing is custom and quoted on request.
Yes. The free plan includes 50 scans, one saved scan, 5 MCP calls per month and an AI code explainer. The site says no signup or credit card is needed to start scanning.
No. The homepage states that scans need no access to the container, because Tagstack reads the public container. The same approach is used to recover containers when admin access is lost.
Yes. It exports a container as JSON that can be reimported into Google Tag Manager, including tags, triggers and variables. The free plan has no container exports, and Starter includes one per month.
Yes. The API runs scans, saves snapshots and returns the technology list for a domain. The MCP server lets assistants such as Claude and ChatGPT run scans and pull reports.
It suits analytics professionals, analytics and marketing agencies and martech sales teams. They use it for audits, recovery, competitor benchmarking and lead qualification.
Yes. It scans any public site with an active GTM container and shows tags, estimated martech spend, server-side GTM and Consent Mode V2 status, and the container's score.