Previewing and Debugging

Previewing is an important quality assurance (QA) step. You can make sure the site looks and behaves as you expect and, using the debugging option, see which tags fire as you browse and interact with the site. (Note: Debugging is not currently available for mobile app containers.)

Previewing (Web)

Google Tag Manager provides you with a preview link. You can share this link with others and when they use it, a preview cookie will be set that enables preview mode just for their browser. When they use the link to navigate to the website, the site will fire the tags in the version they are previewing. Turn off the preview from the Container Versions page (Versions > All Versions in the left navigation).

You can preview any version of a container. A version is essentially a saved snapshot of the container; read Publishing and Versions to learn more.

Previewing (Mobile Apps)

Click Preview > Share Preview from a saved version of your mobile app container. This will generate a link that you can email to yourself and others. When the link is opened, it uses the still unpublished container, and behaves according to the macros and rules in that container.

Debug Console (Web only)

Debugging is a Preview mode option. When you preview a site and debugging is enabled, a console window at the bottom of your browser shows the status of each tag (for example, fired, not fired) in the container. This console window will appear only on your computer as you preview the site and is not visible to your site’s visitors.

A status is displayed for every tag in the container. Each tag's status updates in the console as you browse throughout the site and interact with each page.

  • Fired: The tag was fired.
  • Not fired: The tag was not fired. The status message specifies blocking rules.

To preview the site without the console window, uncheck the debugging option before previewing.