Locating the Unique Device Identifier, or udid, for an iPhone is a fundamental task for developers, enterprise administrators, and users who require precise device identification. This string of characters serves as a permanent serial number that never changes, even if the device is restored or updated. Finding this identifier is essential for tasks such as enterprise app distribution, registering devices for developer programs, or troubleshooting specific network issues. The following guide outlines the most reliable and current methods to retrieve this information safely.
Understanding What a UDID Is
The UDID is a 40-character alphanumeric string unique to every Apple device. It is distinct from the serial number or IMEI, although they are often confused. This identifier is used by Apple’s ecosystem to recognize a specific piece of hardware. Due to privacy concerns regarding app tracking, Apple has made it increasingly difficult to locate this information directly within the iOS settings menu. Consequently, users must rely on specific workflows involving iTunes or Apple configuration utilities to view the raw data. Knowing how to access it is vital for anyone managing multiple devices or developing custom applications.
Method 1: Using Finder on macOS Catalina and Later
With the transition to Apple’s new operating systems, the process has been streamlined for users of macOS Catalina (10.15) and later. The dedicated iTunes application has been split into separate apps like Music and Finder, making the interface more intuitive. To find the identifier this way, you simply connect your iPhone to the Mac using the original USB cable. Once the device appears on the left sidebar of the Finder window, you click on its icon. This action opens a summary page where standard details like storage and version are visible, but the identifier is hidden behind a link.
Revealing the Identifier
To reveal the string, you must click on the "Serial Number" text located near the top of the window. macOS intelligently toggles this display, changing the text from "Serial Number" to "Identifier" upon the first click. A second click is generally unnecessary, as the identifier will populate automatically in the text field after the first toggle. This method is the most visual and straightforward approach for modern Apple computer users, eliminating the need to open a separate music application.
Method 2: Using iTunes on Windows and Older Macs
For users operating with older versions of macOS Mojave or earlier, or for Windows PC users, the classic iTunes application remains the primary tool. After connecting the iPhone to the computer, you must launch iTunes and select the device icon that appears in the top left corner of the interface. This action pulls up the device summary screen, which displays battery health, storage capacity, and backup options. Similar to the Finder method, the serial number is the initial display, requiring an extra step to view the raw data.
Switching the Display Mode
You locate the "Serial Number" field in the top right section of the summary tab. Clicking this serial number toggles the display to show the UDID. Once the identifier appears, you can highlight the text to copy it to your clipboard for pasting into registration forms or developer consoles. It is crucial to ensure that the device is trusted on this computer; if this is the first connection, you must unlock the phone and tap "Trust" to allow the data transfer to proceed.
Method 3: Utilizing Apple Configurator 2
Apple Configurator 2 is a specialized application designed for IT professionals who need to set up and manage large numbers of iOS devices. While it is available for free on the Mac App Store, it provides the most detailed hardware information available. This tool is particularly useful in enterprise environments where devices are supervised and require batch management. If you frequently handle device identifiers, downloading this utility can save significant time compared to toggling between iTunes and web pages.
