Run multiple Firefox versions simultaneously

Updated for 2017-10-31

When developing websites, I’ve found it incredibly useful to be able to run, or install, multiple versions of Firefox on the same computer, side-by-side, simultaneously, concurrently – whatever you want to call it. When it comes to testing, it’s always sensible to see how things are going to be displaying in future browsers, but even more than that, when testing different permissions and profiles on a website, having multiple, separate browsers can really simplify matters.

I run all 4 available channel versions in 64bit mode as it is more secure, stable and snappier with the following details.

Download the full packages!

You will need to download the full package for each version of Firefox, in order to specify the install directory as part of the install process. By default you will be given a stub installer for each channel version, but these are simple (and great!) installers that don’t give you control over various aspects of the install.

The regular download pages for Firefox defaults to downloading stub installers.

Firefox – Stable

"%ProgramFiles%\Mozilla Firefox\firefox.exe" -no-remote -P "stable"

Once you have Firefox Stable installed you will need to create your other profiles. Enter this command into your run window (Win+R) and it will bring up the profile creation UI:

"%ProgramFiles%\Mozilla Firefox\firefox.exe" -no-remote -P

Firefox – Developer

"%ProgramFiles%\Firefox Developer Edition\firefox.exe" -no-remote -P "dev"

Firefox – Beta

"%ProgramFiles%\Mozilla Firefox Beta\firefox.exe" -no-remote -P "beta"

Firefox – Nightly

"%ProgramFiles%\Mozilla Firefox Nightly\firefox.exe" -no-remote -P "nightly"

Firefox – Legacy (3.6.28 – 32bit)

"%ProgramFiles(x86)%\Mozilla Firefox Legacy\firefox.exe" -no-remote -P "legacy"

I also store all the profiles in a single location in Dropbox Google Drive so I can use this setup on other machines, or even with the Portable Apps versions.

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