Legacy runtimes in the App Engine standard environment have reached end of support. Your existing applications using legacy runtimes will continue to run and receive traffic. However, App Engine might block re-deployment of applications that use runtimes after their end of support date. We strongly recommend that you upgrade your legacy applications to the latest supported version to continue receiving security updates and be eligible for technical support.

To migrate to the latest version for your runtime, see:

You should also consider migrating to Cloud Run, the latest evolution of Google Cloud Serverless. Cloud Run is designed to improve upon the App Engine experience, incorporating many of the best features of both the App Engine standard environment and the App Engine flexible environment. To compare features and understand how to migrate, see the App Engine and Cloud Run comparison guide.

If you use the App Engine legacy bundled services, you can either:

The following diagram shows a simplified view of migrating from first-generation runtimes to second-generation runtimes.

Overview of the migration paths for moving your apps to the second-generation runtimes in the standard environment.