Firefox – Run different Firefox profiles concurrently

firefoxfirefox-profilemultiple instancessession

Purpose

Because of my somewhat excessive use of tabs—which often contain PDFs'—I use 64-bit builds of Firefox. It has now gotten to a point where I want to use different profiles; one for my research the other for my day-to-day stuff.

Attempt

  1. Created a new profile called: Research, by running Firefox with the -P CLI arg.
  2. Quit Firefox
  3. Created two shortcuts following the official documentation; linked to:
    • [path to firefox]\firefox.exe -no-remote -P "Research"
    • [path to firefox]\firefox.exe -no-remote -P "default"
  4. Opened each shortcut

Result

Only the fast profile clicked loaded; opening the second shortcut just opens a new Window in the previous profile. Same happens if I open them with inverse order.

Troubleshooting

I tried linking the shortcuts to different Firefox binaries (i.e.: HTguard, Waterfox, Cyberfox) to no avail.

How do I get multiple profiles to work side-by-side; on Windows 8?

Best Answer

You do not need to install multiple versions of Firefox to do this. If you want to have two shortcuts, one which launches the default profile and one which launches a profile named "Research", your two shortcuts should point to:

  • [path to firefox]\firefox.exe
  • [path to firefox]\firefox.exe -P Research -no-remote

It does not matter which shortcut you launch first.

Opening a new instance of your Mozilla application with another profile:

Never use -no-remote to start the "default" profile (the one that is set to open without asking when you launch Firefox). That's because when you launch Firefox, for example, by clicking a link in your mail program, you will get a "Firefox is already running but is not responding" message if the default profile is already in use. The solution is to always start the default profile normally and launch all others with -no-remote. Then it will work.

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