The go2go Playground

About the Playground

The go2go Playground is a web service that runs on's servers. The service receives a Go program, vets, compiles, links, and runs the program inside a sandbox, then returns the output.

This experimental instance of the playground supports the syntax described in the Type Parameters design draft, utilizing the go2go tool.

The best way to provide feedback for the language changes will be on the mailing list Mailing lists are imperfect, but they seem like our best option for initial discussion. When writing about the design draft, please put [generics] at the start of the Subject line and to start different threads for different specific topics.

If you find bugs in the generics type checker, the translation tool, or this playground instance they should be filed in the standard Go issue tracker at Please start the issue title with cmd/go2go:. Note that the issue tracker is not the best place to discuss changes to the language, because it does not provide threading and it is not well suited to lengthy conversations.

We look forward to your feedback.

There are limitations to the programs that can be run in the playground:

  • Not all features of the normal playground are supported. This issue tracks feature parity with
  • The playground can use most of the standard library, with some exceptions. The only communication a playground program has to the outside world is by writing to standard output and standard error.
  • In the playground the time begins at 2009-11-10 23:00:00 UTC (determining the significance of this date is an exercise for the reader). This makes it easier to cache programs by giving them deterministic output.
  • There are also limits on execution time and on CPU and memory usage.

The source code is available at

Any requests for content removal should be directed to Please include the URL and the reason for the request.