I'm using Mavericks and I noticed some of my files have their extensions hidden and others don't. How does Finder decide whether a file extension needs to be hidden?

I know I can prevent this inconsistency by selecting the "Show all filenames extensions" option in Finder Preferences.

1 Answer 1


Finder doesn't decide this - it is a flag saved with the file. The app saving the file sets or clears this flag. You can do a Get Info on a file to toggle this setting on a per file basis.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .