Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

How do I use different default profiles with different instances of Firefox on Mac?

  • 2 replies
  • 1 has this problem
  • Last reply by cor-el

more options

Hello, I am doing automated browser testing with Sahi and I need to have multiple instances of a browser on my Mac at different browser versions, mainly since I don't have multiple Macs available.

So I followed this link: and now I have a copy of Firefox 12.0 and a copy of Firefox 19.0 on my Mac.

But I want Firefox 19 to update automatically and Firefox 12 to never update. But they're sharing the same user profile settings so if I set one, it will affect the other.

What I want is to be able to have both instances installed, have multiple profiles installed for a user, and have v19.0 use one (A) by default with the updates turned on, and have v12.0 with the other (B) with the updates turned off.

Is there a way to do this?

All Replies (2)

more options


You should be able to do this by using the profile manager, and running two different profiles for each setup. By selecting what you sync between them, you should be able to import all your bookmarks and history without also importing all the settings. Have a look at this page in the knowledge base.



more options

You need to add -P profile to the command line to make sure to start each Firefox version with its own profile. Easiest to do this is to use a (bash) shell script to launch Firefox.

If you want to run multiple versions at the same time then add the -no-remote switch

I use code like this on Linux, but it should work on Mac with the proper installation path and profile name as shown in the Profile Manager.


cd /Applications/
./firefox -no-remote -P test-XX

Modified by cor-el