Mac OS X has a commandline tool called "defaults". It lets you set certain properties, for example:

enable the "Debug" menu in Safari:

defaults write com.apple.Safari IncludeDebugMenu 1

What is the most useful "hidden" "defaults write ..." command you have ever issued?


There is a database of these hidden settings at secrets.blacktree.com. They also offer a free PrefPane you can install to twiddle these (instead of cutting and pasting from the website into Terminal).


My favorites:

defaults write com.apple.Safari TargetedClicksCreateTabs -bool TRUE

The above forces all links to open in new tabs, instead of new windows.

defaults write com.apple.screencapture location "/path/to/save/screenshots" 

This one saves your screenshots somewhere else, other than your desktop.

defaults write com.apple.screencapture type PDF

And this one changes the format of your screenshoots to PDF. I am sure some might find this one handy.

defaults write com.apple.dock showhidden -bool YES

ghosts out the icons of apps that are currently hidden.

Well, actually, the most useful I ever wrote was, IIRC:

defaults write NSGlobalDomain NSInterfaceStyle NextStep

but that doesn't do anything on versions of OS X with Aqua :-(.

  • ah, NextStep, the sweet memories... :) – Kris May 6 '09 at 12:45
  • actually, that was Rhapsody - which by default used a Platinum interface style. – user448 May 6 '09 at 16:03
defaults write com.apple.desktopservices DSDontWriteNetworkStores true

Disables the creation of .DS_Store files on Network Shares.

defaults write com.apple.iTunes AppleDisplayScaleFactor .75

Shrink iTunes to 75% normal size. It's off-topic, and not really that useful (unless you're using a small display), but fun enough that I can't resist posting it. It works for other apps too, e.g. To shrink Calculator.app by 50%:

defaults write com.apple.Calculator AppleDisplayScaleFactor .5
  • how is this off-topic? i think it's awesome and i didn't know it yet – Kris May 29 '09 at 14:02

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