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In November 2018, the Google Analytics team started to send some of you a note to let you know that in October 2019 they will begin to sunset the Google Analytics for mobile apps reporting and the Google Analytics Services SDK. We had a comprehensive post about this important update.

In June 2019, if you had a Google Tag Manager legacy mobile app container, you might have received an email with a subject line. “Google Tag Manager: Important information about your legacy mobile containers”. Because of its definitive change in direction for mobile app tracking towards Firebase Analytics and Google Analytics App & Web, Google needs to begin the process of decommissioning the GTM legacy mobile app containers. Legacy mobile app containers that have already been created will continue working until March 2020, but you will not be able to publish new changes after October 31, 2019.

After acquiring it in 2014, Google launched the revamped Firebase – Google’s platform for mobile developers across iOS and Android – at Google I/O in 2016 and introduced a new version of Google Tag Manager for mobile apps (Android V5 and iOS V5). After three years of support, Google decided to turn down the legacy containers (Android V4 and iOS V3). When you access the legacy GTM Android or iOS guides, you will find prominent notes to encourage you to use the latest Tag Manager + Firebase implementation.

Key Dates

The depreciation process of the GTM mobile legacy containers will follow this timeline:

[Already in place] June 30, 2019: You are no longer able to create new containers of the “Android (Legacy)” or “iOS (Legacy)” types. You can continue to create other container types, including the latest “Android” and “iOS” types.

October 31, 2019: You will no longer be able to publish new changes to legacy mobile app containers. The container version that is currently live as of this date will continue working in mobile apps, but the containers will not be in a read-only mode.

March 31, 2020: The legacy mobile app containers will no longer work in your apps. Requests will return a 204 (no content) response. Following this date, legacy mobile app containers will be removed from the Google Tag Manager UI and will no longer be accessible.

Update: Google has decided to extend the key dates in this turndown process in order to provide adequate time to update to the latest version of Tag Manager for mobile apps. With this extension, your legacy mobile app containers will not be affected until at least January 31, 2020. They are actively working to finalize the new dates for this turndown process and will update their Help Center as soon as more specific information is available.

What’s new in the GTM Mobile Container UI?

Container type:
Previously, when you were creating a new GTM container, you used to see the following options:

The GTM UI previously allowed you to create Legacy iOS and Android containers.

But from now on, you will see the following options:

Legacy containers are no longer an option in GTM.

App configuration & experiments: The new version of Tag Manager for mobile apps does not include Value Collection variables nor Content Experiments. To implement these functions, you should use Firebase Remote Config instead. Remote app configuration and A/B testing functionality are not a part of Firebase.

You can now control Remote Config and A/B testing completely through the Firebase UI.

Lookup tables: Lookup tables are now supported for mobile app containers.

The useful Lookup Table variable is now available in Android and iOS containers.

Data layer variables: Data layer variables are not supported on the new app containers. There are other variable types available as alternatives.

While data layer variables are no longer available, there are some new user-defined variable types available.

Third-party tag templates: Mobile app containers include an expanded list of third-party templates.

Third-party tag templates available in the new GTM app containers


We highly recommend starting to put your development plan to migrate from Legacy GTM to GTM + Firebase. Contact us to help you with your migration steps.

Happy Tagging!