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Each time a page with the Google Tag Manager container snippet loads, it will request the gtm.js JavaScript. Subsequently, any GIF requests or other calls deployed through Google Tag Manager (and configured properly with Rules matching the current page) will be made. To help ensure that your tags are firing successfully, you may find it beneficial to use a debugging tool. The following table lists a number of tools for use with the most common browsers.

AllFirebug Lite
All (Windows-based)Fiddler
ChromeBuilt-in Developer Tools (e.g. Resources)
FirefoxLive HTTP Headers
SafariBuilt-in Activity window

Once you install the tool and have it set up, you can open the web page you want to troubleshoot and see the web traffic analysis in the tool. First, you want to make sure that the page in question is indeed requesting the gtm.js JavaScript (and that the ID appended matches your GTM ID). As long as you see this request, you can be sure that the Google Tag Manager container is implemented. You should then see the requests for all tags fired with Google Tag Manager on the given page. If you do not see your tags firing, please ensure that:

  1. Your container snippet is implemented following the instructions in the Quick Start Guide.
  2. The ID listed in your container snippet matches that of the container you are managing in the Google Tag Manager interface.
  3. You have saved any changes to your rules and tags, and those changes have been published in Google Tag Manager.
  4. Your rules are configured properly (with the correct match types) to execute your tag(s) under the current conditions.
  5. You have cleared or bypassed your cache by performing a hard refresh