Requires following advice from other commenters and applying some elbow grease to make this addon working, but after doing that, it works perfectly like how it is in Google Chrome. This should really be a core feature that should be included in Firefox.

Unfortunately it seems that the addon doesn't work immediately upon installtion. But there is a fix. Amazing addon after you add a quick fix! I am on a Windows machine and this is what I did. First, you need to locate the Profile Switcher config folder. This is the address:

C:\Users\Username\AppData\Roaming\nulldev\FirefoxProfileSwitcher\config

Just replace Username with your own username. If there is no file named "config.json" in there, make it. Ensure that you have this in there:

{
"browser_binary": "C:\\Program Files\\Mozilla Firefox\\firefox.exe"
}


Confirm that Windows recognizes it as a JSON source file. Restart Firefox. The addon should now work!

Doesn't work. Went through each and every step, when i click the extension icon there is a little ball with nothing inside as if the window is empty.

Works great with Firefox on Arch Linux. You do, however, have to download a helper (firefox-profile-switcher-connector-bin) from the AUR, but it's well worth it. The instructions are clearly explained after you install this plugin (in the "Complete Setup"). You also have to apply a workaround to get the connector working (something that isn't well documented):

1. Create ~/.config/firefoxprofileswitcher/config.json
2. Add to this file: {"browser_binary": "/usr/bin/firefox"}

Would be good if this extra "hidden" step (workaround) was not needed.

BTW - it's not the devs fault that this extra step is required - it's because of changes to Firefox. It's much easier using this plugin instead of opening a new tab and then entering "about:profiles" in the address bar and then selecting the profile you want to switch to.

Works on macOS May 2025 but requires the workaround as described in github directory issue 106.

Was using this extension as long with ff-pswicth tool installed (required in order to work correctly) but now, this extra tool seems to request additional privileges for some unknown reason (app management + passkey access). Is this app compromized?

nonfunctional. Clicked on widget. Told me to download some Windows software, close, install, reopen. Did that. Profiles show up, but nothing happens when clicked. Nothing happens when double clicked. Nothing special happens when right clicked (just save page as, select all, show source). Has superfluous animations, such as when the gear icon is clicked, it slides the settings pane up, and when save or cancel is clicked, slides the pane down. A lot of flash with close to zero functionality as far as I can tell. Good for profile listing, but nothing else, really. It's easier just to put a bookmark to about:profiles on the bookmarks bar. Helper widget does not uninstall itself, just fakes doing something but leaves the directory populated with files, has to be deleted manually. If it's erroring on files being in use during uninstall, it doesn't tell you, just closes the window (you need to exit FF to delete its directory).

Doesn't work on Zen browser, tried on Flatpak and AUR installation. After completing the setup steps it keeps saying setup is incomplete.

Works nicely after applying workaround as found in the GitHub repo (Issue 106)

It won't let me switch profiles

It won't let me switch profiles and was last updated in 2022. Shame.

Doesn't work on firefox dev's and regular options, but works on Floorp (Firefox fork) which I use

Non funziona, nonostante l'installazione di un software separato richiesto obbligatoriamente.
Pessimo.

Has anyone been able to get this to work? I installed the additional software with the wizard, and added the extension to all my profiles, but the profile buttons are not responsive.

Used to work flawlessly, but seems the dev has stopped updating it.

Insanely useful after properly setting it up.