Google Tag Manager overview

Google Tag Manager is a tag management system that allows you to quickly and easily update:

  • Tags and code snippets on your website or mobile app, such as those intended for traffic analysis and marketing optimization. You can add and update AdWords, Google Analytics, Floodlight, and 3rd party or custom tags from the Tag Manager user interface instead of editing site code. This reduces errors and frees you from having to involve a web developer when configuring tags.
  • Configuration and flag values of mobile apps. Instead of rebuilding and deploying new mobile app binaries, you can use the Tag Manager interface to change configuration values (such as timeouts, ad positioning, game play dynamics) and turn on flag-enabled features.
In this article:

What is a tag?

A tag is a snippet of code that sends information to a third party, such as Google. If you don't use a tag management solution such as Tag Manager, you need to add these snippets of code directly to files on your website or mobile app. With Tag Manager, you no longer need to maintain each of these code snippets in your source files. Instead, you specify the tags that you want to fire, and when you want them to fire, from within the Tag Manager user interface.

How it works

Tag Manager for web works via its own container tag that you place on all your website pages. For mobile, Tag Manager is deployed via an SDK for Android or iOS. The container replaces all other manually-coded tags on your site or app, including tags from AdWords, Google Analytics, Floodlight, and 3rd party tags. (See a list of supported tags.) Once the Tag Manager container tag has been added to your site, you update, add, and administer additional tags right from the Tag Manager web application.

For mobile containers, a default container is used to set initial configuration values until the first time a container is downloaded. Once the app has connected to the internet and downloaded a container, it will never use the default container again. Applications periodically check for container updates, typically every 12 hours.

Your Tag Manager account allows you to administer the tags for one or more websites or mobile apps. Although you can set up multiple Tag Manager accounts from a single Google account, you’ll typically only need one Tag Manager account per company or organization. Read Setup and Workflow to learn more.

Watch this video to learn more about the basics:

Setup for web

To manage tags using Tag Manager:

  • Go to to create an account (or to access an existing account).
  • Create a container for your site in the account.
  • Add the container snippet to your site.
  • Migrate any hardcoded tags (such as AdWords or DoubleClick tags) from your site’s source code into Tag Manager.

Do I need to migrate my tags all at once?

We do recommend migrating all of your tags as a best practice. However, if you need to hold off on migrating a few of your tags, Tag Manager will fire it's tags alongside any hardcoded tags just fine.

You’ll then be ready to do all of your future tag management for your site via the Tag Manager user interface. For more information, read Setup and Workflow and watch the following video:

Tag Manager for mobile apps

In addition to working with tracking codes on mobile apps, Tag Manager is also useful for managing configuration values that you want to change in the future, or that can change conditionally. Instead of defining constant values in your mobile app, you can make them dynamic and use Tag Manager to manage the rules that govern how these values change. Examples include:
  • dimensions and locations of ads served in your application, for example, to change ad banner height based on screen size
  • game settings
  • user interface settings, such as differences between platforms
  • localized strings determined by device language

Setup for mobile apps

  • Go to to create a Tag Manager account (or to access an existing account).
  • Create a container for your app in the account (select the "Mobile Apps" option).
  • Download and implement the Tag Manager for Mobile SDK.
Read Setup and Workflow to learn more.

Next steps

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