Mozilla Firefox is one of the most popular web browsers out there today. The firefox browser has the ability to support multiple users or profiles. This functionality works more as a way to provide the ability to separate data and configuration rather than to provide any kind of security.
A Profile in Firefox is a set of files that hold the personal information of the user, such as passwords, bookmarks, history and user preferences. These files are stored in a different location in the file system, usually in the user home directory. In a multi user environment, this can provide some privacy depending on the permissions assigned to the users, especially in Linux or Unix environments.
The way to change profiles is using the Profile Manager in the browser. You can use the Profile Manager to create, remove, rename and switch profiles. You will however need to start the Profile Manager separately to perform any of the above mentioned functions.
To start the Profile Manager, you will need to start the firefox application with the command line option -ProfileManager or -P. In Linux, you can use the command line interface to do the same. If you use some shortcut, then you can update the shortcut to add the option.
$ /usr/bin/firefox -P
This will open a window or popup screen with all your profiles listed. There are options or buttons to create, rename and delete profiles in this dialog. In order to switch the user (or profile), just select the profile you want and then click on Start Firefox button in the lower right hand side.
If you want to make the currently selected profile the default and you don’t want to be prompted again, then select the checkbox that says “Use the selected profile without asking at startup” before click the Start Firefox button.
You can further manage the profiles using the create, rename and delete button in the dialog which are mostly self explanatory….it does what it says and the wizard should walk you through the process.
When you have multiple profiles, you might sometimes want to use multiple profiles at the same time or concurrently. By default, Firefox allows you to only use only one profile at a time. Every time you start a new instance, it will connect to the already started instance and profile. In order to start two (or more) instance using different profiles, you will have to use –no-remote option in addition to the -P option.
$ /usr/bin/firefox --no-remote -P
There is another option called –new-instance that works pretty much the same way as –no-remote. You can use either of the options to start a new instance of the browser instead of a new window in the running instance.
If you already know the name of the profile that you want to use, then you can include that along with the -P option as an argument as well. This will eliminate the need to select the profile in the pop up dialog. This is beneficial when creating shortcuts. You can create multiple shortcuts to the browser which will open different profiles.
$ /usr/bin/firefox -no-remote -P <profilename>