Choose your preferred environment
Standard environment
Optimized to scale nearly instantaneously to handle huge traffic spikes.
Most cost-effective for applications that have significant periods where they are not serving traffic.
OpenJDK based Java runtime supports the standard public Java library.
Doesn't impose a security manager--your code won't be restricted by Java permissions issues.
Ubuntu OS
The Java 8 runtime is no longer supported.
Flexible environment
Full open source language runtimes.
Use any framework, library, or binary of your choice.
Code is portable to anywhere that supports Docker containers.
Most cost-effective for applications that serve traffic continuously.
No free tier. Application always has a minimum number of running instances. Most cost-effective for applications that serve traffic continuously.
Ubuntu OS
Choosing an environment
You can run an App Engine application in two environments, the standard environment and the flexible environment. See a summary of differences between the two environments.