How do I change the default port (9000) that Play uses when I execute the "run" command?

Play 2.x

In Play 2, these are implemented with an sbt plugin, so the following instructions are really just sbt tasks. You can use any sbt runner (e In Play 2, these are implemented with an sbt plugin, so the following are really just sbt tasks. You can use any sbt runner (e.g. sbt, play, or activator). Below the sbt runner is used, but you can substitute it for your sbt runner of choice.

Play 2.x - Dev Mode

For browser-reload mode:

sbt "run 8080"

For continuous-reload mode:

sbt "~run 8080"

Play 2.x - Debug Mode

To run in debug mode with the http listener on port 8080, run:

sbt -jvm-debug 9999 "run 8080"

Play 2.x - Prod Mode

Start in Prod mode:

sbt "start -Dhttp.port=8080"

Play 2.x - Staged Distribution

Create a staged distribution:

sbt stage

For Play 2.0.x and 2.1.x use the target/start script (Unix Only):

target/start -Dhttp.port=8080

For Play 2.2.x & 2.3.x use the appropriate start script in the target/universal/stage/bin directory:

target/universal/stage/bin/[appname] -Dhttp.port=8080

With Play 2.2.x & 2.3.x on Windows:

target\universal\stage\bin\[appname].bat -Dhttp.port=8080

Play 2.x - Zip Distribution

To create a zip distribution:

sbt dist

For Play 2.0.x and 2.1.x use the start script (Unix Only) in the extracted zip:

start -Dhttp.port=8080

For Play 2.2.x use the appropriate script in the [appname]-[version]/bin directory:

[appname]-[version]/bin/[appname] -Dhttp.port=8080

With Play 2.2.x on Windows:

[appname]-[version]\bin\[appname].bat -Dhttp.port=8080

Play 1.x

Change the http.port value in the conf/application.conf file or pass it command line:

play run --http.port=8080

Play 2.0-RC4

It is important to include quotes around the play command you want to run. In my case without the quotes play would still run on port 9000.

play "run 8080"

Alternatively you could run the following from the play console (type 'play' to get to the console)

run 8080

Hope this helps someone.

via sbt settings:

...
.settings(PlayKeys.playDefaultPort := 8855)
...