RCDefaultApp is a Mac OS X 10.2 or higher preference pane that allows a user to set the default application used for various URL schemes, file extensions, file types, MIME types, and Uniform Type Identifiers (or UTIs; MacOS 10.4 only). MacOS X uses the extension and file type settings to choose the application when opening a file in Finder, while Safari and other applications use the URL and MIME type settings at other times for content not related to a file (such as an unknown URL protocol, or a media stream).

RCDefaultApp also allows setting the application when digital cameras or FireWire webcams such as iSight are connected to the computer. For completeness' sake, there are also settings that mimic the existing "CDs and DVDs" preference pane, which allows setting the action to take when various types of CDs and DVDs are inserted into the computer.

Finder's Get Info panel can be used to set the default application for file extensions and file types, but it's not intuitive. Apple's Internet preference pane in MacOS X 10.0 through 10.2 (Jaguar) allowed you to set the Web and Email applications, but no other URL handlers. In MacOS X 10.3 (Panther), these settings have moved to Safari's and Mail's preferences — meaning you have to run those applications if you want to choose to not use them. Similarly, the digital camera preference is located in Image Capture's preferences, and the webcam preference is a checkbox in iChat's preferences. RCDefaultApp allows the setting of all of this information, and ties everything together in one preference pane.

RCDefaultApp also allows entries to be disabled, such as URL schemes that have security issues ;-)


This screenshot shows the section where the default application for various Internet services can be set, similar to the preference in Safari.app and Mail.app.

This shows how to set the application for an extension; just pick the desired application from the list.

This shows the section to set the action for when various types of media are inserted or turned on, similar to the preference in Image Capture.app and iChat.app. The CD and DVD preferences are also duplicated here with easier access to the "Perform action at login" setting.

This shows the section where each application's possible settings can be seen and assigned at once. The small button in the bottom right is for RCDefaultApp "About" information.

This shows RCDefaultApp as it appears in System Preferences.app.


RCDefaultApp is freeware. Please see our About page for more information.


We are always interested in bug reports, suggestions, comments, or any other feedback on RCDefaultApp. Send feedback to here.


2.1, September 2009

  • Added ability to ignore creator codes for extensions (MacOS X 10.4 and above).
  • Added IM selection (i.e. aim:// protocol) to the Internet pane.
  • Added Blank/Video BD (Blu-ray) and DVD Device to the Media pane on MacOS x 10.5 (Leopard and above).
  • Added Spanish localization. (contributed by Emilio Perez Egido)
  • Only show one version of an application on 10.4 and above, per system limitation.
  • Fixed bug with the File Types tab on Intel machines. (reported by Brian Holloway)
  • Improved discovery of existing settings.
  • Built with a 64-bit Intel binary to work with the Snow Leopard System Preferences.
  • Fixed a couple of other minor bugs.

2.0.1, November 2006

  • Added Dutch localization. (contributed by Simon G Maasdam)
  • Updated Japanese localization. (contributed by E-WA)
  • Updated French README. (contributed by Claude Le Mestric)
  • Sort application names in the popup menu.

2.0, March 2006

  • Built as a universal binary for use on Intel Macs.
  • Added "Apps" section to assign multiple extensions etc. at once.
  • Added "Media" section to allow setting actions when digital cameras and webcams are plugged in.
  • Disallows setting an application for the "app" extension and related items, as this causes problems.
  • Uses localized descriptions for URL schemes.
  • Changed to use a sheet for the About information, triggered by a small "i" button.
  • Fixed a couple of other minor bugs.

1.3, May 2005

  • Fixed operation on MacOS X 10.4.
  • The <default> option works in more places now.
  • Added support for Uniform Type Identifiers (UTIs) on MacOS X 10.4.
  • Fixed potential <disable> problem following 2005-004 security patches for Mac OS X 10.2 and 10.3.
  • Fixed Italian localization; most of it was not working.
  • Slightly improved ability to find application information.

1.2.1, December 2004

  • Fixed operation on MacOS X 10.2.

1.2, December 2004

  • Added ability to add custom extensions, MIME types, and OS types
  • Typing letters will now jump to the nearest matching entry in the list.
  • Added Italian localization. (contributed by Alessio Ciregia and TranslationFactor)
  • Added Chinese traditional and simplified localizations. (contributed by Shoekai Yeh)
  • Added French README file. (contributed by Claude Le Mestric)
  • Added RSS selection (i.e. feed:// protocol) to the Internet pane. (suggested by Håkan Björk)
  • Fixed bugs with handling malformed application Info.plist files.

1.1.1, May 2004

  • Added Japanese localization. (contributed by E-WA and Fumio Yamamoto)
  • Added French localization. (contributed by Gwendal Roué)
  • Added German localization. (contributed by Alexander Nouak)

1.1, May 2004

  • Added ability to disable entries so that URL schemes etc. can be turned off. (suggested by Paul Hoffman)

1.0, April 2004

  • Initial release.