Every single Mac computer manufactured by Apple is assigned a Unique Device Identifier (UDID). Unlike your serial number, which is printed on the bottom of the case and used for warranty repairs, the UDID is a long, complex 40-character alphanumeric string that acts as a permanent cryptographic identifier for your specific hardware.
You generally only need to know your Mac’s UDID if you are an app developer registering your machine with the Apple Developer Program to install beta versions of macOS, or if your company’s IT department requires it to enroll your Mac into their Mobile Device Management (MDM) security platform. Because it is a secure identifier, Apple hides it deep within the System Information tool.
How to Find Your Mac’s Unique Device Identifier (UDID)
You can find the UDID by digging into the hardware overview report.
- Click the Apple Logo in the absolute top-left corner of your screen.
- While the Apple menu is open, press and hold the Option (⌥) key on your keyboard.
- Watch the first item in the menu. “About This Mac” will instantly change to System Information…
- While still holding the Option key, click System Information…
- A complex window will appear. In the left-hand sidebar, ensure that the very top category, Hardware, is selected.
- Look at the main panel on the right side under “Hardware Overview.”
- Look for the line item named Provisioning UDID (or sometimes simply Hardware UUID on much older Macs).
- This is your 40-character identifier. It will look something like this:
00008103-00123456789ABCDE.
To ensure you do not make a typo when sending this to your IT department or the Developer portal, simply double-click the long string of text to highlight it, and press Command + C to copy it perfectly to your clipboard.