Ever had the sit­u­a­tion where you have synced your iPhone (to iTunes OS X) and hap­pen to sync both the con­tacts from your Address Book and Google Con­tacts? Or, just hap­pen to add some­one’s new con­tact info as anoth­er con­tact-card? Well, here’s how I cleaned and merged dupli­cate con­tacts so that my Address Book per­forms like a champ.

1. Launch Script Edi­tor (Applications/AppleScript/Script Edi­tor)
2. Paste the fol­low­ing code snip­pet

   tell application "Address Book"
       set biglist to {}
       set theGroup to count every person
       if not (exists (group "Duplicate Entries")) then
           make new group with properties {name:"Duplicate Entries"}
       end if
       set the_names to the name of every person as list
       repeat with i from 1 to number of items in the_names
           set this_Name to item i of the_names
           set theName to name of person this_Name as string
           if this_Name is not in biglist then
               copy this_Name to end of biglist
           else
               add (people whose name is theName) to group "Duplicate Entries"
           end if
       end repeat
       save addressbook
   end tell

3. Save your new­ly cre­at­ed script (would usu­al­ly default to ~/Documents/AppleScripts/), and just open/run it

Now, the eas­i­est way to fig­ure out if its run­ning or not (at least for me) was to run the Activ­i­ty Mon­i­tor and sort by CPU. I sim­ply just wait­ed to see if Address Book would climb to the top doing 90+, and back down to nil. When this is done, you should be able to see a group called “Dupli­cate Entries”. From there, you may now sort through the details and delete the ones that you don’t need.

Note: You can also do a quick merge via Address Book itself from dupli­cate con­tacts. How­ev­er, you won’t be able to see which con­tacts are being merged as its just a set-it-and-for­get kind of deal. If you do not care and sim­ply just want to get rid of those dupes, you can do so by doing the fol­low­ing:

1. Launch Address Book
2. Select Card from its menu
3. Then, select Look­ing for Dupli­cates… and just go through the fol­low­ing prompts after search results fin­ish­es