Download from here.
So you want a portable browser on your Mac?
Unfortunately, starting from Mountain Lion, Mac OS has unknown publisher apps disabled for installation by default. Enabling them back requires administrative privileges, which the majority of Mac users will never do, so most folks have stopped releasing portable apps for Mac. To enable unknown sources, you have to go “System Preferences” of your Mac. Then click on “Security and Privacy”. There go to “General” tab. Click on the small paddle lock icon below and enter your admin password. Now switch “Allow apps downloaded from” to “Anywhere” and confirm you actually want to “Allow from Anywhere”. You are all set now, let’s get the portable app. Go to my site by following the link in the description. There you will find a link to the latest version on Mozilla Firefox Portable at my cloud storage. If I will be forced to use a password, the password will also be published on my site. Then download the English package. By the way I also have portable browsers available in other languages and for other platforms like Windows, so go out check my site if you need them. Download the .dmg file, then click on it in your Downloads folder. The installer will open. Just drag the Firefox icon to Applications folder icon, and here you go, now you have a portable Firefox in your Apps. I call this bundle Izzyfox, and it has many cool tweaks and other goodies like automatic ads blocking and other speed improvements. Also note this is a portable installation, meaning your profile complete with passwords, bookmarks, history and other preferences is stored inside the app. So if you need to back it up or transfer to another Mac, just quit the app and copy the file to a thumb drive. You may run Izzyfox directly from your thumbrive, iPod or any other external drive and copy it to any machine. There is no problem with updates, but if you want Izzyfox to become your default browser, please don’t use the built-it Firefox feature, or it will make your browser non-portable anymore. This is a known portable software limitation. I will release a script allowing to make Izzyfox Portable a default system browser as I did for my other portable apps, and post the link to it on the same page on my site. I will also announce it on my YouTube channel, so make sure to like and subscribe.