I have two different installations of Firefox. This is done so that one installation can be automated using Marionette, while I use the other for regular web browsing. I created the second installation by making a copy of the first application folder. I gave them two different names and icons. The former is called "Firefox" and the latter is called "Firefox work browser".

I have set my default browser to "Firefox work browser".

Profile separation, browsing and concurrently running these applications all works correctly, except for when I try to open a link - it always opens in the "Firefox" browser, not in the "Firefox work browser", despite the latter being selected as my default browser:

Firefox work browser selected in dropdown list, Firefox is not selected

This is clearly a bug, so I'm trying to find a workaround here. I'm guessing the browser selection process depends on some regex or string.startswith() function. I'd try renaming the work browser but that involves migrating profiles, which is somewhat cumbersome.

  • 2
    Why do you think it is a bug? All you did was renaming the application itself, its bundle id as defined in Info.plist is still the same. Can you switch the usage (use Firefox for regular browsing, FirefoxSomething for automation)?
    – nohillside
    Dec 18, 2023 at 12:00
  • I think it is a bug because I selected a specific default web browser in System Settings, which is not being used. This menu makes no mention of bundle id. If the bundle id is what is being used rather than the application names shown in the dropdown menu, then the dropdown menu should not display multiple browsers with the same bundle id, or at least give a warning for conflicting bundle ids.
    – Appeltaart
    Dec 19, 2023 at 10:49

1 Answer 1


MacOS references the app by its bundle identifier, which is the case of FireFox, is org.mozilla.firefox.

Unfortunately, this does cause problems for multiple versions of the same app.

Historically, macOS would always open the newer version by default. I doubt that changing the name is significant, but I note that "Firefox work browser" comes after "Firefox" in an alphabetical sorted list.

  • 1
    Using a tool like Link Unshortener might help (haven't tried it for that specific use case though).
    – nohillside
    Dec 18, 2023 at 13:58

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