Choose your preferred environment
Standard environment
Optimized to scale nearly instantaneously to handle huge traffic spikes.
Ubuntu OS
The PHP 5 runtime is no longer supported.
Flexible environment
Open source runtimes capable of running any framework, library, or binary.
Greater CPU and memory instance types.
Can access resources in the same Compute Engine network.
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.