How to Downgrade Firefox to Firefox ESR in Windows

One of my friends got tired of rapid Firefox version updates issued by Mozilla. They are released a new version every month and sometimes it breaks the web apps that people have been using for years. So my friend asked me for a solution and Is suggested her to switch to Firefox ESR (extended support release) – it does not get too many updates and still stays secure.

Starting from version 67 of Firefox browser, if you manually downgrade the version of the browser for any reason, it will display an error window and won’t proceed. The only options available are “Exit” and “Create new profile”. But what if we want to use the existing profile with the different version or browser under different channel (ESR, Release, Beta etc)? In that case, you have to use a special method allowed by Firefox.

Here is how you can downgrade from other Firefox channels to Firefox ESR in Windows:

  1. Download Firefox ESR from
  2. Close all the open Firefox windows.
  3. Make a backup of the Firefox profiles folder (%APPDATA%\Mozilla\Firefox\Profiles\). Just copy all the contents of this folder to another location.
  4. Install Firefox ESR over the existing Firefox installation by choosing to Upgrade during the setup. If you cannot go through the installation, you can also manually copy the files from Firefox ESR setup (use 7-Zip to extract the files) to your Firefox installation folder.
  5. Right-click on the Firefox shortcut on Windows desktop and select Open file location.
  6. In the folder that opens, click in the location bar, type cmd.exe and press Enter.
  7. In the command prompt window, type firefox –allow-downgrade and press Enter.
  8. This is it, you are all set. You have downgraded to Firefox ESR.

The benefit of this method is that you do not have to create new Firefox profiles. It uses the existing user profile without any problems. But in order to stay on the safe side, you should make a backup of the Firefox user profile folder before proceeding.