How To Check UDID Of IPhone: The Authoritative Guide For All IOS Models

To find an iPhone UDID (Unique Device Identifier), connect the device to a Mac or PC and navigate to the Summary or General tab in Finder or iTunes, then click on the Serial Number label to toggle the display to the UDID string. Modern iPhones (iPhone XS and later) utilize a 25-character format with a hyphen (00008020-XXXXXXXXXXXXXXXX), while older models use a 40-character hexadecimal string without hyphens.

Technical Requirements and Pre-Extraction Checklist

Before attempting to retrieve the Unique Device Identifier, it is essential to understand that this string is a permanent hardware-linked signature. Unlike the Identifier for Advertisers (IDFA), the UDID cannot be reset by the user through software settings or factory wipes. It is primarily utilized by developers for registering devices in the Apple Developer Program to facilitate the installation of ad-hoc beta applications or for Mobile Device Management (MDM) enrollment in enterprise environments.

Essential Gear and Prerequisites:

• Hardware: An iPhone (any generation) and a functional data-sync cable (Lightning to USB-A/C or USB-C to USB-C depending on the model).
• Operating System Compatibility: macOS Catalina (10.15) or later uses Finder; macOS Mojave (10.14) or earlier and Windows 10/11 require the latest version of iTunes.
• Trust Relationship: The iPhone must be unlocked, and the user must tap Trust when the Trust This Computer prompt appears to allow data communication between the device and the workstation.
• Estimated Duration: 2 to 5 minutes depending on the method chosen.
• Security Standard: UDID should be treated as sensitive data. Never share this identifier on public forums, as it uniquely identifies your physical hardware to Apple’s servers.

Comprehensive Identification Workflows for All Platforms

There are several verified methods to extract a UDID, ranging from native OS tools to developer-centric software. Choose the method that best aligns with your current hardware setup and technical proficiency.

Step 1: Retrieving UDID via macOS Finder

Since the release of macOS Catalina, the device management functionality previously housed in iTunes has been integrated directly into the Finder application. This is the most efficient method for modern Mac users.

1. Connect your iPhone to your Mac using the appropriate data cable.
2. Open a new Finder window and locate your iPhone under the Locations section in the left-hand sidebar.
3. If this is the first time connecting, click Trust on both the Mac and the iPhone screen, entering your passcode if prompted.
4. Within the Finder window, ensure the General tab is selected in the top navigation bar.
5. Look at the top section of the window where your iPhone model name, storage capacity, and battery level are displayed. Directly below the model name, you will see the Serial Number.
6. Click on the text that displays the Serial Number. The text will cycle through the Model Number, the IMEI, and finally, the UDID.
7. Once the UDID is visible (the long string of letters and numbers), right-click (or Control-click) on the identifier and select Copy UDID.

Pro-Tip: If the identifier does not change when clicked, ensure the device is fully synced and that you are clicking specifically on the sub-text area beneath the iPhone’s name.

Step 2: Extracting UDID on Windows Using iTunes

Windows users must rely on iTunes to interface with the iOS file system for identifier extraction. Ensure you have downloaded iTunes directly from the Microsoft Store or Apple’s website to guarantee driver compatibility.

1. Launch iTunes and connect your iPhone to the PC.
2. Click the small iPhone icon located near the top-left corner of the iTunes interface.
3. Navigate to the Summary tab in the left-hand menu.
4. In the center pane, you will see a box containing information about your device, including the Serial Number.
5. Click on the Serial Number label. It will first change to the UDID.
6. To capture this string, navigate to the Edit menu at the top of the iTunes window and select Copy, or simply press Control plus C on your keyboard while the UDID is displayed.

Warning: Be cautious when using third-party "UDID Grabber" applications on Windows. These often contain adware or may compromise device security. The iTunes method is the only Apple-sanctioned approach for Windows.

Step 3: Using macOS System Report (The No-Software Method)

This method is highly effective for technical users who do not want to interact with Finder or iTunes interfaces. It pulls the data directly from the USB bus controller.

1. Plug your iPhone into your Mac.
2. Click the Apple Menu in the top-left corner of your screen and select About This Mac.
3. Click on More Info or System Report (depending on your macOS version).
4. In the System Information window, look at the sidebar and select USB under the Hardware category.
5. In the USB Device Tree on the right, find and click on iPhone.
6. In the bottom pane, look for the field labeled Serial Number. Note that for modern iPhones, the string listed here under the USB tree is actually the UDID.
7. Highlight the string and copy it for your records.

Step 4: Utilizing Xcode for Developers

For software engineers and QA testers, Xcode provides the most detailed hardware breakdown, including the UDID and Provisioning Profile status.

1. Open Xcode on your Mac.
2. Navigate to the Window menu in the top bar and select Devices and Simulators.
3. Select your connected iPhone from the list on the left.
4. The Identifier field in the main pane displays the UDID.
5. This interface allows for easy copy-pasting and also provides the exact iOS build version and architecture details necessary for debugging.

Technical Parameter Comparison: UDID vs. Other Identifiers

Understanding the difference between the various strings associated with an iPhone is critical for accurate reporting and development.

Troubleshooting Common Extraction Failures

Despite the straightforward nature of UDID retrieval, hardware and software handshake issues can occur. Below are common failure scenarios and their technical resolutions.

• Scenario: iPhone Not Appearing in Finder or iTunes

  
  
  
  • Root Cause: Faulty USB cable, dirty Lightning/USB-C port, or a failed "Apple Mobile Device Support" driver on Windows.
  • Actionable Fix: Inspect the port for lint using a non-metallic tool. Replace the cable with an MFi-certified (Made for iPhone) cable. On Windows, open Device Manager, locate Universal Serial Bus devices, and update the Apple Mobile Device USB Device driver.

• Scenario: Clicking Serial Number Does Not Toggle to UDID

  
  
  
  • Root Cause: The device has not established a "Trusted" handshake with the computer, or the software version is outdated.
  • Actionable Fix: Disconnect the iPhone, go to Settings > General > Transfer or Reset iPhone > Reset > Reset Location & Privacy. Reconnect the phone and select Trust. Ensure you are running the latest version of macOS or iTunes.

• Scenario: UDID Format Looks Different Than Expected

  
  
  
  • Root Cause: Apple changed the UDID format starting with the iPhone XS, XS Max, and XR (A12 Bionic chip).
  • Actionable Fix: Do not be alarmed if your new iPhone has a shorter UDID with a hyphen (e.g., 00008020-000123456789). This is the standard format for all modern ARMv8.3-A architecture devices and newer. Older devices will still show a 40-character continuous hexadecimal string.

• Scenario: Copy Function Is Greyed Out

  
  
  
  • Root Cause: System permissions or UI focus issues in macOS Finder.
  • Actionable Fix: Use the Command plus C keyboard shortcut while the UDID is visible, even if the right-click menu is unresponsive. Alternatively, use the System Report method mentioned in Step 3.

Frequently Asked Questions

Does a factory reset change the UDID of an iPhone?

No, the UDID is a permanent identifier tied to the physical hardware. Performing a factory reset, DFU restore, or updating the iOS version will not change the UDID. It remains constant throughout the lifespan of the device.

Is it safe to give my UDID to an app developer?

It is generally safe if the developer is reputable and requires the UDID to add your device to an Ad-Hoc distribution list for beta testing. However, since the UDID identifies your hardware specifically, do not share it with unknown parties or on public websites, as it can be used to track device history in enterprise databases.

Can I find my iPhone UDID without a computer?

Officially, Apple has restricted apps from accessing the UDID directly since iOS 6 for privacy reasons. While some websites claim to provide your UDID via a downloadable "Configuration Profile," these methods carry security risks. The most secure and reliable way to find your UDID is by using a physical connection to a Mac or PC.

Why is the UDID different from the UDID found in my "About" settings?

The "About" section in the iOS Settings app (Settings > General > About) does not actually display the UDID. It displays the Serial Number, IMEI, and Model Number. The UDID is an internal hardware identifier that Apple intentionally hides from the standard user interface to protect user privacy.

What is the difference between a 40-character and a 25-character UDID?

The 40-character UDID was the standard for all devices from the original iPhone through the iPhone X. It was generated using a SHA-1 hash of hardware IDs. Starting with the iPhone XS/XR and newer, Apple moved to a new 25-character format (8 characters, a hyphen, and 16 characters) which is not a hash but a direct identifier provided by the I/O Registry.

Optimize Your iOS Development Workflow

Retrieving the correct UDID is the first step toward successful ad-hoc deployment and rigorous device testing. Ensure your records are updated with these identifiers to maintain seamless integration with the Apple Developer Portal and your internal MDM solutions.