While no extensions have been reported to be incompatible with Firefox Portable, some extensions will extend the portability of Firefox Portable beyond the defaults.

Start FirefoxPortable.exe again to ensure that Firefox Portable is using your local profile.

Copy everything from the local profile folder to the Profile folder on your USB device.

Take care that you are clearing the right Profile folder.

Delete everything from the Profile folder on your USB device.

Open your USB device, and browse to the installation folder, then Data, then Profile.

This launcher ensures that Firefox runs correctly in a portable environment, and cleans up after itself when it is finished to ensure no personal information is left behind.) Now close Portable Firefox. (Always run FirefoxPortable.exe from the installation directory NEVER run firefox.exe from the subfolders. Run Portable Firefox once and answer the setup questions.

Open the folder which starts with a series of random characters and ends in Default, or your profile's name if you have more than one. Follow the instructions on this page to locate your profile.Copy your local Firefox profile to your USB device:

Portable mozilla firefox free download