Harrsh Patel

Posted on Oct 8, 2021

How to setup Firefox Developer Edition on Ubuntu

#firefox #ubuntu #developer #mozilla

Do you want to install and use Firefox Developer Edition on your Ubuntu and don’t know how to go about it?! If your answer is yes, then this article is for you. Am sure you’ve seen some documentations out there but in this one we will add Firefox Developer Edition to our Unity launcher. You’re welcome! 😉

Please follow the steps below…

Step 1
Download the firefox*.tar.bz2 file from Mozilla’s website.

Step 2
Open Terminal.

Step 3
Navigate to the folder where the file is saved.

Step 4
Copy firefox*.tar.bz2 file to the /opt folder.

sudo cp -rp firefox*.tar.bz2 /opt

Step 5
Delete the downloaded firefox*.tar.bz2 file.

sudo rm -rf firefox*.tar.bz2

Step 6
Navigate to the /opt directory.

cd ~
cd /opt

Step 7
Un-tar the firefox*.tar.bz2 file in opt folder.

sudo tar xjf firefox*.tar.bz2

Step 8
Delete the firefox*.tar.bz2 file in opt folder.

sudo rm -rf firefox*.tar.bz2

Step 9
Change ownership of the folder containing Firefox Developer Edition /opt/firefox

sudo chown -R $USER /opt/firefox

Step 10
Create the Firefox Developer Edition's shortcut

nano ~/.local/share/applications/firefox_dev.desktop

The content of this file is,

[Desktop Entry]
Name=Firefox Developer 
GenericName=Firefox Developer Edition
Exec=/opt/firefox/firefox %u
Terminal=false
Icon=/opt/firefox/browser/chrome/icons/default/default128.png
Type=Application
Categories=Application;Network;X-Developer;
Comment=Firefox Developer Edition Web Browser.
StartupWMClass=Firefox Developer Edition

Step 10
Mark the launcher as trusted and make it executable.

chmod +x ~/.local/share/applications/firefox_dev.desktop

I hope this article has helped you to set-up your new Firefox Developer Edition.

Thank you

Top comments (36)

Francisco Zapata • Jul 15 '22 • Edited

Thanks a lot bro!!!
Only one note: "StartupWMClass=Navigator" worked for me to avoid duplicated icon on dock
I have Ubuntu 22.04

46and2 • Aug 29 '22

For some reason it didn't help. I had to set it to StartupWMClass=firefox-aurora on my Ubuntu 22.04.1.

andrei-the-developer • May 8 '23

This issue is likely related to the .desktop file of your Firefox Developer Edition. Specifically, the StartupWMClass property in the .desktop file may not be set correctly. The StartupWMClass property helps the GNOME Shell to associate the running application instance with the correct .desktop file and, consequently, the right icon in the dock.

To fix the issue, follow these steps:

1)Open the Firefox Developer Edition and then open a terminal.

2)In the terminal, run the following command to get the WM_CLASS property of the Firefox Developer Edition:

xprop WM_CLASS

After running the command, your cursor will turn into a crosshair. Click on the Firefox Developer Edition window. The terminal will display the WM_CLASS value, which should look something like this:

WM_CLASS(STRING) = "firefox", "Firefox Developer Edition"

Take note of the second value (in this example, "Firefox Developer Edition").

3) Open the .desktop file for Firefox Developer Edition with a text editor. The file should be located in ~/.local/share/applications/ and named firefox_dev.desktop. If you can't find it there, look for it in /usr/share/applications/.

nano ~/.local/share/applications/firefox_dev.desktop

4) In the .desktop file, find the StartupWMClass line and update its value to match the second WM_CLASS value you found in step 2. In this example, the updated line should look like this:

StartupWMClass=Firefox Developer Edition

5) Save the changes to the .desktop file and close the text editor.

6) Restart your Firefox Developer Edition, and the issue should be resolved. The new instance should now be associated with the existing icon in the dock.