Java 6 Runtime Support Shutdown

On June 11, 2013, in App Engine Java SDK version 1.8.1, we announced that the ability to deploy Java 6 applications would be removed in an upcoming release, and this ability was removed in version 1.9.0 on February 26, 2014. Existing apps would continue to run in Java 6, but they could not be re-deployed. We are removing support of Java 6 due to the expense of supporting old Java versions and because most of the Java developer community has moved to newer Java versions.

To complete the move away from Java 6, we are announcing that support for Java 6 apps will be removed beginning on March 20, 2017: all free tier applications with no billing account will be migrated to Java 7.

For billed applications, support for Java 6 apps will be removed beginning on June 28, 2017 : a forced migration will occur on a weekly basis after June 28, 2017, but customers will have the chance to re-migrate to Java 6 after each weekly forced migration to Java 7.

To temporarily re-migrate your app back to Java 6 after each week's forced migration to Java 7, click the Whitelist button in the upper right of the console dashboard for the project containing the Java 6 app:


On July 26, 2017, the forced migration to Java 7 will be final, and Java 6 support will be removed permanently.

Known incompatibilities between Java 6 and Java 7.

For details about known incompatibilities, refer to the Oracle Java documentation.

You may wish to follow this upgrade process to migrate from an existing application deployed on Java 6 to a Java 7 runtime:

  1. If you don't have it already, obtain access to the application code.
  2. Download the most recent Java SDK.
  3. If you haven't already done this, install a Java 7 JDK on your machine, because current App Engine Java SDKs are Java 7-only.
  4. Test the app with the App Engine development appserver.
  5. Deploy this application using this current version of the SDK: you can use the SDK appcfg command, or the equivalent in ANT, in Maven, or in the Eclipse GPE plugin.

  6. After you deploy, your application will run in the Java 7 runtime.

Shutdown timetable

The following table lists the Java 6 support shutdown schedule:

Date Event
March 20, 2017 All free tier applications with no billing account are migrated to Java 7. This is permanent.
June 28, 2017 For billed apps only, beginning of weekly migrations. Customers have the option to migrate back to Java 6 if they need more time.
July 26, 2017 For billed apps only, final migration to Java 7. After this date, Java 6 support is permanently turned off.

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