The Firefox web browser is offered in various versions (called channels by Mozilla), just like Google Chrome or Opera are. Most Firefox users are on the stable release channel. This channel is suited for all home users who just want to use the browser. It receives the least amount of updates and extended periods of testing.
The Firefox ESR release is similar to that, but with the difference that it has been designed for organizations and corporate environments. Home users can still download and use it but they will notice that many of the changes that ship in the stable channel are not applied to ESR immediately. In fact, major changes are only added to the ESR version in 42 week cycles instead of the usual 6 week cycle.
That's great if you do not like changes like the new Australis theme that is coming up, as ESR versions will get it a lot later than all other Firefox editions.
The Beta channel is six weeks ahead of the release channel. You find new features here that are tested by Mozilla that will eventually land in the stable channel. It is updated more often than the stable channel, but not as often as the Aurora channel. This channel is six weeks ahead of the Beta channel.
Then there is the Nightly channel, which more or less receives daily updates. Nightly versions are cutting edge and you usually find new features added to them first before any other version of the browser. They are more prone to issues and errors due to the time Mozilla and testers have to find and fix bugs.
Special builds, like Nightly UX, are available as well. They are usually created for a specific purpose, to test new features like Australis, without adding it to one of the official channels directly.
Sometimes, you may want to switch from one channel to another. Maybe you have downloaded the Nightly version of Firefox but do not like the fact that it is update that often, and want to switch to the stable channel instead. Or, you are running stable but want to run nightly as well to find out what is new and cool. Or, you may want to switch from Stable to ESR.
Switching Firefox channels
It is actually not that difficult to switch channels. You can install Firefox stable, beta, aurora , nightly, ESR and special builds on the same system next to each other. They will all share the same profile by default, which you may or may not want. Note that some channels use the same installation directory, and that you need to install them in different ones to avoid one replacing the other.
The advantage of that is that you can access all your bookmarks, got all of your extensions and preference changes that you have made in the past.
The disadvantage that some extensions may be incompatible, some preference may have changed, and that you may run into other issues.
It is recommended to run different profiles for each channel you are using. This also means that you can run multiple Firefox versions next to each other on the system at the same time.
When you install Firefox, you should select the custom installation option as it enables you to specify a different installation directory, or check up the directory that Firefox will be installed in
The default installation folders are:
- Firefox Stable: \Mozilla Firefox\
- Firefox Beta: \Mozilla Firefox\
- Firefox Aurora: \Aurora\
- Firefox Nightly: \Nightly\
- Firefox ESR: \Mozilla Firefox\
As you can see, the stable, beta and ESR builds share the same installation directory by default. If you do not want that, change the installation directory by selecting custom installation during setup.
If you do not, the new version that you are installing will overwrite the old one.
This outlines that you have two options.
- If you want to move from one channel to another, install the new version in the same directory.
- You can install it in a different directory so that you can access both versions.
I recommend to use the second option, as you will avoid all kinds of issues associated with the first. If you do not need the other version afterwards, simply uninstall it on your system to remove it.
There is a third option. I do not really recommend it as things can go wrong here quite easily. The pref("app.update.channel", "release"); determines the update channel your browser is on. To change it without installation, simply modify the channel name, in this case release, to another channel.
Note that you can only modify the preference directly in the Firefox program directory locate under \defaults\pref\channel-prefs.js.
Open the file in your plain text editor of choice and modify the channel here. Restart the browser and you should be updated to the new channel.
It is hard coded in here, so do not bother editing it in about:config, as it won't work this way.
I have been running Firefox Nightly and Stable on the same system forever, and never really ran into any issues doing so, even when both browsers shared the same profile (I switched to independent profiles eventually though). The best option to change from one Firefox channel to another is to install the channel you want on the system to do so.
Now Read: Run 2 Firefox profiles at the same time