If you are big into hacking into your iPhone or development, then you must have come across the need for UDID number. UDID number basically is a 40 character long alphanumeric character set that is unique to your iPhone. Unless you are hacking or cracking into the device, chances are you may never need this number, but what is wrong in knowing every set of value associated with your device? So here is a little step by step tutorial to help you find the UDID number of your iPhone.
(Image Via: whatsmyudid)
Step 1) Connect your iPhone to computer and fire up iTunes.
Step 2) In iTune look at the left pane, and click once on the device which will open the summary tab.
Step 3) Once you are in the summary window, you will see Serial number there, no that is not your UDID.
Step 4) All you need to do now, is to click on the Serial Number once and boom, there you have your UDID.
Step 5) Clicking Ctrl+C would copy this serial number and you can easily copy it in a place like Wordpad to save it.
There you have it, it is as easy as that to find the UDID of your iPhone. Remember this ID is unique to your iPhone so do not compare it with your friends, and better if you keep the ID to yourself and not let anyone have access to it.