Cool Tools for Google Tag Manager

Sharing cool tools on a hot summer day. Five tools I use to help make sense of Google Tag Manager containers.

Cool Tools for Google Tag Manager
Photo by Nattu Adnan / Unsplash

In this post, I share a few tools I've been using lately for data analytics, tracking, and marketing, specifically looking at tools related to Google Tag Manager. As a software engineer, I've encountered a need to work with analytics tools quite frequently. I would much rather be coding than "button clicking" and thanks to these tools I can spend less time navigating dashboard menus and more time making sure the data I need is sent to the right place.

I hope that this article, or at least the links attached, find their way into your favorites bar and save you some time, as they have for me.

Request Map Generator

This tool allows you to quickly scan a website and visualize its requests. This is valuable for determining what is loading on a website.


  • There's little in terms of analysis beyond requests and their timing data.
  • I would love to see a better visualization of how the requests affect load time (sorta like a flame graph).

Overall, great tool with helpful export features. Keep up the good work Simon Hearne.

For example, in the screenshot below, I'm loading Plausible Analytics, Adobe Typekit, and Google Fonts.

Request Map for Tricities Media Group's site

Tag Stack - tracking stack from any website tracks martech and pixels used by websites. Hit scan on a website and uncover its tracking setup. Tagstack also offers a way for analytics freelancers and agencies to search for potential clients that use specific tools like GTM Server-side.

Tag Stack is unique among the tools in this list in that 1. it has paid tiers and 2. also integrates lead prospecting. It provides several scans for free per month and then offers a one-time purchase plan to buy credits or unlimited subscription plans with different feature options. Rather than just a container analysis tool, Tag Stack allows you to scan a website and reverse engineer the container's config. This allows you to scan sites you don't have access to (without needing to download/copy the container config) and, in the pro tier, even download the GTM JSON, potentially allowing you to clone a container if you lose access to the container in GTM. Pretty nice!

In addition to the scan functionality, Tag Stack also includes a lead search engine. Accoridng to the site, it has over 1.4 million containers scanned and searchable. This makes the service a valuable prospecting tool since users can query based on not using modern standards or based on technology (if, for example, you specialize in tagging Acme Social pixels). You can think of it as but for analytics data.


  • There are a few small bugs and styling glitches, but this tool is pretty new and doing a lot of heavy lifting, so it's not a big complaint.
  • I'd love to see a mapping style feature like GTM Utility and a report generation tool with data similar to GTM Visualizer.
  • I would find it interesting to be able to show the history of scans to see how active a container is. (Ex: Does the site owner regularly make updates to their configuration, or is it stale). This is more of a feature request than critique though.
  • In the original version of this post I had a critique about the pricing gap from free to the pro tier, but the pricing has been updated in a way that fixes that (see below).

Shoutout to Lucas Kosta, the creator!

After I wrote this post, the creator contacted me and acted on some critiques I put in the original version. The big change was adding the one-time/pay-per-use plan. To me, that makes this tool much more accessible to all types of users and allows users to upgrade for more advanced features or pay-per-use for what features they need. I'm really excited about the future of this service and seeing what can be done with this data.

Walk Through

After completing a scan, the user is shown a page reminiscent of GTM's previewer, except with the addition of an audit and more detail on containers without needing access.

Tag Stack Scan Results

Notice how it shows the various features the container has and lets me dive into the individual tags and triggers:

Tag Stack Scan Containers

When clicking a tag, you can see more details, including parameters and connected triggers.

Tag Stack Scan Tag Details

GTM Visualizer

This tool allows you to paste in your config and then see it broken down, illustrating which relationships are present throughout your container. Viewing these details is helpful since it let's you, at a glance, understand where and how various tags and triggers are used. Yes, you can find similar information in the GTM console, but this format is much easier to digest.


  • The UI design is a bit dated, but that's fine.
  • It would be nice to be able to click on a trigger/tag/variable's name and view it in its relevant list. Instead, the list is static (though the colors are a helpful touch).

As an added benefit, this tool is open-source (though not maintained), which is reassuring since it requires you to paste in your config or sign in. Big thanks to yuhui/gtmvisualizer on GitHub.

Using the tool is super easy. Just paste in a GTM JSON or Sign In with your Google Account (I didn't try the latter).

Screenshot of GTM Visualizer

GTM Utility

Visualize Google Tag Manager Container
Google Tag Manager audit tool provides container visualizer and tabular view of all dimensions and parameters. GTM Utility is a FREE community tool.

I really like how it shows everything in a graph network. This view helps to visualize how the different Tags, Triggers, and Variables interact.


  • You can't drag around the canvas, instead relying on scroll bars.
  • Because of how the scroll bars are setup you can't use a full page screenshot tool.
  • There's no export option. Ideally, it should allow saving as a image, PDF, and/or interactive HTML file. If you trying saving as a HTML file, the functionality breaks.
  • When you select a node it shows only the relationships connected to that node. This is nice! But I would also like to see a side bar appear with more details about the node rather than just the name.

Overall, it's a great tool and a great price (free)! Kudos to Igor Smirnov 🔥

Using the tool is very similar to GTM Visualizer. Paste in your GTM JSON or Sign in with Google.

Screenshot of GTM Utility

Claude AI

Perhaps this one is unconventional, but with the announcement of Claude's new Artifact feature (new as of Summer 24), tools like Claude can now code their own interfaces for your data. To test this functionality, I tried to upload a GTM container and see what it could do. Turns out Claude is really good at interpreting containers and even building much of the functionality of GTM Visualizer (all in about 5 seconds).


  • The entire interface is a React component. Good if you want to add this to a site, but for some reason, with larger container files, it would crash.
  • The screenshot shows iteration 2. In the first iteration it didn't show the IDs correctly. To get to iteration 2 I gave it the file as an example, which it used to fix the bug.
  • For the other iterations I decided to push it further asking for shadcn components to make the interface more modern and also for it to use Framer Motion (cause why not). The environment is apparently sandboxed somewhat because it couldn't use Framer. It was able to use chadcn, but I ran into a the issue where it crashes.
  • The crash issue almost seems like a memory problem (I'm pretty sure the React code is being rendered client side, but not sure), but it could also be a React error. Overall, really neat, and I'd like to pull down this code and try to build a modernized version of some of the older tools in this post.

Claude is obviously not primarily a GTM analysis tool, so these critiques are a bit tongue-in-cheek.

Screenshot of Claude AI Interpreting a GTM Container

At the risk of sounding like Buggs Bunny, that's all folks. If you're looking for help with your data and analytics, I'd love to chat. I am a certified Zaraz developer, which is a Cloudflare owned GTM alternative that takes the heavy lifting off of user browsers and onto the edge, with benefits including speed, interactivity, and privacy control. To get in touch, send over an email or directly book a paid 1-hour call where I'll try to work through your problem and/or give suggestions:

I realize this is a departure from the more technical content I typically post on this blog, but rest assured, my drafts are piling up with content covering my approach to testing, an article on building a faster version of dig for name server lookups, and a deep dive from keyboard to cloud.