Anyone who’s been using a Mac for a long time has probably accumulated a large number of Address Book contacts. Over time, your contacts can end up looking pretty messy, leaving you with a bit of a mess to clean up, such as removing duplicate entries.
One way to remove duplicate entries from your Mac’s address book is to sift through your contacts manually, find out what’s different between the two entries, and do your best to combine them into a single entry – but that’s a real chore, right? Fortunately, Apple has built an easy way to remove duplicate contacts right into Address Book!
To merge duplicate entries, just select two or more duplicate contacts, and press the Shift, Command, and | key (on the upper case of the back slash “\” key) at the same time. Address Book then does all of the merging for you! Nice! Unfortunately, you’ll still have to scroll through all of your contacts to fix your duplicates using this method.
If you’d rather merge ALL of your duplicate entries at once, just launch Address Book, select the Card menu from the menu bar, then select “Look for Duplicates…”. Address Book will then track down and merge all of your duplicate entries in a single swoop.
There’s also a great app called Contacts Cleaner on the Mac App Store that will do all your merging for you as well (although it does cost $5). Click here to grab Contacts Cleaner from the Mac App Store!