Macs have always been good about opening documents using the correct application. Going back to the original Mac, every file created by a program has had embedded within it information about the application that created it. Unlike earlier versions of that other operating system, you’ve never had to attach a suffix to a filename, like “.doc”, to tell the system what to open it with. You just double-clicked on the file, and it opened within the appropriate application. Thankfully, “the light” has shown through Windows, and those other “95-percent-ers” now have this feature as well.

This information is also used to tell the graphical user interface (GUI) which icon to display on the application itself and all documents created by the application. In fact, this icon is your first clue as to what application will be used to open the file when you double-click it.

Some files, like Quicken data files, are only associated with one program with which you would want to open them. But what about more generic file types, like PDFs, JPEGs, or even the aforementioned “.doc” files, that can be opened by many different applications installed on your Mac? How do you, for example, tell the operating system that you want to open PDF files using Preview and not Adobe Reader?

The answer lies within the Get Info window. Click on a document (or data) file, and then either: select File > Get Info; type Command-I; or right-click (with your new Apple Mighty Mouse) and select Get Info from the resulting contextual menu.

In the fifth section down the Get Info window you’ll see “Open with:” and a pop-up menu button. Clicking this button will present a list of applications the Mac thinks can be used to open the file. Make your selection from the list, if you want to use something other than the system default. If you want to use something else altogether, click “Other” at the base of the menu and browse through the Finder. Whatever your selection, it applies only to the file you originally selected.

Now, what if you want all your PDF files to always open in Preview instead of Adobe Reader? Do you need to select every file and make the change individually? No. Just use the “Change All…” button. Fast! Easy! Effective!

© 2005 Peter F. Zimowski