MDN wants to learn about developers like you:

Once you've selected a runtime, you can access the runtime settings:

Use this to:

Runtime info

Permissions table

A table summarizing app permissions for the current runtime, indicating for each API and each app type whether access is allowed (✓), denied (✗) or whether the user is prompted (!).

Device preferences

A table listing where the preferences can be edited that are made available in the runtime via the Preferences service. These are platform-level configuration values exposing the same set of data as Firefox's about:config, but for the device.

Because these preferences are highly security-sensitive, you need to disable the DevTools restricted privileges setting before you can modify them.

Device settings

New in Firefox OS 2.5.

A table listing, and letting you edit, the settings that can be controlled in the Firefox OS Settings app. Most things on the device which have a UI control to change, such as volume and alarm, are found in Device Settings.

Settings such as these are less sensitive than the device preferences and can be modified without removing the restricted privileges setting.

To use this feature you must be running WebIDE in Firefox 38 or later, and connecting to Firefox OS 2.5 or later.


A command to take a screenshot from the runtime.

Document Tags and Contributors

 Contributors to this page: wbamberg, openmando
 Last updated by: wbamberg,