Confluence's Developer Mode is a system property setting that tells Confluence to enable various debugging features

that are not otherwise exposed to users. To enable Developer Mode, you should start Confluence with the following system property set.
 -Dconfluence.devmode=true 

If you are writing a Confluence extension and want to check if Developer Mode is active, you can call ConfluenceActionSupport#isDevMode() if you have an action available ($action.devMode in Velocity templates), or Boolean.getBoolean(ConfluenceActionSupport.DEVMODE) if you don't.

Developer Mode Features

Currently, enabling Developer Mode will activate the following features:

Confluence 2.0 より前

Confluence 2.0