Firefox is a great browser, but one thing it doesn’t let you do is open multiple instances of it. This can be useful say, if you have a dual-screen computer or if you’re a beta tester and would like to compare versions of Firefox. For me, Firefox won’t let me open more than one window from the Start bar, so I use this trick to pass that restriction.
To allow the running of multiple instances, follow these steps:
- Open Notepad or a basic text editor
- Copy-paste this into the editor:
@echo off set MOZ_NO_REMOTE=1 start "" "C:\Program Files\Mozilla Firefox\firefox.exe" -p set MOZ_NO_REMOTE=0
- Save the file with a .bat extension at the end. Use whatever name pleases you.
- Click on the .bat file (instead of the Firefox shortcut) to open Firefox. The Profile Manager will appear, allowing you to choose a profile.
- Open Terminal
- Enter the following command, which will open up the Profile Manager:
- For each new instance of Firefox that you want, click the Create Profile… button to create a new profile.
There are additional steps that make profiles auto-launch, which will better simulate running multiple instances:
- Open up the Finder, and navigate to where the instance of Firefox that you want to set up is located.
- Right-click the icon, and select Show Package Contents
- In that window, navigate to “Contents/MacOS”
- Rename “firefox-bin” to “firefox-bin1”.
- Create a new text file, and paste in this code:
/Applications/Firefox.app/Contents/MacOS/firefox-bin1 -P ProfileName &
*ProfileName should be the name of the profile you created in the Profile Manager.
- Save the file as “/Applications/Firefox.app/Contents/MacOS/firefox-bin” (no extension).
- Run this command in the Terminal:
chmod +x /
- Congratulations! You should be able to run multiple instances of Firefox.