How can I disassociate a file extension from any default app?

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brsm1990 Author

Level 2

250 points

How can I disassociate a file extension from any default app?

Can anyone tell me how to clear the default app association? I guess at some point an app I installed associated itself to a file I don't want it associated with or maybe I did it by accident. I can only figure out how to change it to something else, but what if I want to change it to nothing? The "Open with:" drop down only lets me choose another app but there is no option for "no default".

What does "Change All..." do and I why can't I click it?

Related question: https://discussions.apple.com/thread/252219481

Posted on Dec 26, 2020 5:18 AM

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Answer 1

dialabrain

Level 10

135,827 points

Dec 26, 2020 5:20 AM in response to brsm1990

There is no "no default" and Change All only works when you change to a different default.

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Answer 2

brsm1990 Author

Level 2

250 points

Dec 26, 2020 5:44 AM in response to dialabrain

Let me rephrase the question then: How do I get it back to "that"?

Clearly there is a problem of apps grabbing associations that don't/shouldn't belong to them and there are other cases where the same file type belongs to multiple application types. I want to be asked when I click on a file not have it open automatically in some program that it doesn't belong to and won't be able to read it.

How do I make it "ask me" when I click on a file. This isn't rocket science and macOS can't be this screwed up can it?

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Answer 3

brsm1990 Author

Level 2

250 points

Dec 26, 2020 5:51 AM in response to dialabrain

I don't want it to be associated to anything by default, like an unknown file. Is the OS really so poorly designed that once you associate a file with something it must forever be associated with something even though the OS clearly has the possibility for "no association"?

.dat is a perfect example of a file type that should not be associated to anything, especially not a video player.

Is this really something that's been a problem since 2011 that they never fixed?

Once you install some crappy third party software that associates itself with any random file extension you are stuck with that forever until you find another app you want to associate to the file extension? Horrible horrible UI.

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Answer 4

VikingOSX

Level 10

123,248 points

Dec 26, 2020 5:53 AM in response to brsm1990

Sure. Because macOS is a UNIX operating system beneath Finder, it needs to associate a file extension with some application, and so does the Launch Services database that Finder uses. If you make up a bogus file extension, the operating system has no means to map that extension to any opening application, and you lose double-click and right-click, open with access to the file. That serves no purpose from a Finder perspective. Prior to Big Sur, the operating system would also assign a special icon to the file as a green/black exec icon, but with Big Sur, the file is just a plain icon.

Refrain from creating alien file extensions.

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Answer 5

brsm1990 Author

Level 2

250 points

Dec 26, 2020 5:35 AM in response to dialabrain

There definitely is a default of no association. Look:

Related question, why is Brave showing a different association than Finder? That's annoying.

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Answer 6

dialabrain

Level 10

135,827 points

Dec 26, 2020 5:43 AM in response to brsm1990

That is not a default of "no association". That is the system not recognizing what app should open a non-existent extension. I knew I shouldn't have answered. :)

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Answer 7

dialabrain

Level 10

135,827 points

Dec 26, 2020 5:46 AM in response to brsm1990

Right or Control click on a file and choose "Open With". You will be given a list of what apps the system thinks can open the file. It's not all that difficult.

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Answer 8

dialabrain

Level 10

135,827 points

Dec 26, 2020 5:50 AM in response to brsm1990

I have better things to do. Enjoy.

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Answer 9

brsm1990 Author

Level 2

250 points

Dec 26, 2020 6:08 AM in response to VikingOSX

I can't refrain if a program associates it without asking me first. Is there no way to undo or prevent that?

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