Find Unique Device Identifier (UDID) on the iPhone
Your Mac, iPhone, and iPad all have a Universally Unique Identifier (UUID) assigned. These codes are specific to each device and, similar to a serial number, they are used by developers to identify each one individually. Here’s what you need to know.
What is a UUID?
A UUID is a string of letters and digits that forms a unique pattern. Your Mac, iPhone, and iPad each have one UUID, and no other device shares it. It’s similar to a serial number in that regard, but whereas serial numbers are used to identify your device by Apple and your cellular carrier, developers usually use the UUID instead.
Normally, you wouldn’t need to know (or access) your UUID. But if you’re registering a device as part of the Apple Developer Program so you can install beta software, you’ll need it. App developers might also ask for your device’s UUID so that they can provide builds that will only work on that particular device.
How to Find Your Mac’s UUID
Click the Apple logo in the menu bar, and then click the “About This Mac” option.