Install and use different versions of Firefox in Ubuntu

You may want to use an old version of Firefox in your system because your automation tests are dependent on it. Use the following instructions to install any version of Firefox in your Ubuntu machine.

• Go to https://ftp.mozilla.org/pub/firefox/releases/ and navigate through the links to the correct installer you want to use.
• Get the URL of the installer by combining URL in address bar with the installer name. Suppose that you want to install Firefox 38.0.6, then the installer URL is ftp.mozilla.org/pub/firefox/releases/38.0.6/linux-x86_64/en-US/firefox-38.0.6.tar.bz2 .
• Execute the following commands to download and install a chosen Firefox version(e.g. 38.0.6).

wget ftp.mozilla.org/pub/firefox/releases/38.0.6/linux-x86_64/en-US/firefox-38.0.6.tar.bz2
tar -xjvf firefox-38.0.6.tar.bz2
sudo mv firefox /opt/firefox38.0.6
sudo ln -sf /opt/firefox38.0.6/firefox /usr/bin/firefox

You can verify whether Firefox is installed properly using the command:

firefox --version

You can maintain different versions of Firefox using the instructions given above. Then just create a symbolic link to the specific version you want to use.