The Preview app used to be the default app to open PDF files. For some obscure reason, this is being changed into Photoshop every now and then.

If this happens, I do this:

  • Right click on a PDF file, Open With...
  • For some reason Preview isn't even in that list, so I click Other
  • Select Preview, check the 'Always Open With' box, and click Open
  • Then I right-click the file again, Get Info
  • The "Open With" part shows Preview, and I click the "Change All" button

And then it's OK for a while. But a few days later, without me changing any settings, for some reason PDF files are being opened with Photoshop again :(

Is there a way to prevent an app from binding file types to itself without my permission?

FYI I'm using macOS High Sierra 10.13.2 (17C88).

  • Does this happen with other apps as well, or just with Preview?
    – IconDaemon
    Mar 12, 2018 at 19:08
  • @IconDaemon Just with Preview
    – RocketNuts
    Mar 16, 2018 at 11:47
  • any luck trying my answer? Mar 20, 2018 at 10:16

1 Answer 1


Try rebuilding your Launch Services database.

In Terminal:

/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

Then reboot immediately.


  • Thanks Matt, as soon as the situation occurs again, I will give this a try and let you know the results!
    – RocketNuts
    Mar 25, 2018 at 10:48

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