I installed 2 Firefox apps at the same time in my Mac, one for work and one for personal. How to do that? First, install Firefox and in Applications, rename Firefox.app to My-personal-Firefox.app . Then, install Firefox again, it will be Firefox.app. Here is what I did with FirefoxNightly, but it's possible to do so with Firefox: https://imgur.com/a/Zy2iDkK (note: for more convenience, I have changed the app's icon)