Tips: Running multiple instance of Firefox
Sorry if there are any spelling or grammatical errors, I’m learning English… :)
I bet many of you didn’t know that you can run more than one instance of Firefox. Instance is different from just another Firefox’s window. It’s completely use different configuration file. So, your preferences like add-on, cookie, proxy setting, etc are different. Running another instance is just like running another browser instead of Firefox itself.
What’s the benefit of running multiple instance than only one instance? IMO there are two point of view that we can look at it. The first is from developer point of view, by running multiple instance web developer did not need to run another browser if only want to test the session log in. e.g the developer wants to be guest user and logged user at the same time. They just need to run another instance since every instance have different session or cookie.
The second is from end user point of view. Imagine that you have visited some “private” site and then your friend borrow your laptop for a moment. When your friend start typing in URL address bar in browser and oopss… he/she found some “interesting site” that you have visited(It’s not my experience :)). It can be avoided by clearing all history from that site but there is more smart way by using another Firefox profile.
So, how can we run multiple instance of Firefox? well basically when you run Firefox it was invoked by using this command:
$ firefox
But ever you notice that the are plenty of options that we can pass to Firefox. Just type in your terminal:
$ firefox -h
Regarding our topic, the option that we need to pass to Firefox so it will run another instance is:
$ firefox -no-remote -P
When command above invoked it will bring a “Profile Chooser” window. In normal situation when you never create a profile before, your profile name is “default”. So, let’s try to create another profile by clicking “Create Profile…” button and named “private” for the profile name. When you want browse some “interesting site” you can use that profile by using command below:
$ firefox -no-remote -P private
But remember, as you can see at picture above. There is an option “Don’t ask at startup”, every time you run Firefox your default profile now is “private”. So, we need to set back the profile to “default”. Just close the instance of running “private” profile and then run the following command:
$ firefox -no-remote -P default
