Upgrade an existing application

You must upgrade your applications to the latest supported runtime version to continue receiving security updates and be eligible for technical support.

The process of upgrading an existing app depends on the runtime version that your app currently uses:

  • PHP 5.5 (first-generation runtime): You must migrate your app to the latest supported PHP version. PHP 5.5 has reached end of support on January 30, 2024. Your existing PHP 5.5 applications 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. To migrate to the latest supported version of PHP, see Migrate from PHP 5.5 to the latest PHP runtime.

  • PHP second-generation runtimes (after end of support): To upgrade to a supported version of PHP, update the app.yaml file by specifying a version of PHP that you want your app to run. For example:

    runtime: phpVERSION

    Where VERSION is the PHP MAJOR and MINOR version numbers. For example, to use the latest PHP version, PHP 8.3, specify 83. For more information, see the PHP runtime overview.