iOS Device UDID

A UDID is the unique serial number that identifies an iOS device — a key piece of information in the Ad Hoc distribution flow. This page covers what a UDID is, how to fetch one, and how it fits into Pgyer's distribution flow.

What a UDID Is

The UDID (Unique Device Identifier) is a unique serial number that identifies an iOS device, like an ID card — every device has its own.

A UDID is a string of letters and numbers, typically either 40 or 25 characters long. For example:

37f2f993bae681636e30e74b04d6b8955ba36f29

00008120-000CABCD02ABC1234

Retrieving a Device's UDID

You can pull a UDID from a computer using iTunes or Xcode, but the process is fiddly. Pgyer offers an easier route — scan the QR code below with an iPhone or iPad:

Or open this URL directly on an iOS device:

https://www.pgyer.com/tools/udid

Follow the on-page prompts to install Pgyer's profile. If the device has a passcode, enter it when prompted.

UDIDs and Ad Hoc Distribution

For an iOS app signed with Ad Hoc to install on a given device, that device's UDID must first be registered in the app's provisioning profile (.mobileprovision).

Typical flow:

1. The person who wants to install the app retrieves their UDID via the self-service UDID tool.
2. They send the UDID to the developer.
3. The developer registers the UDID in the certificate and re-packages the app.
4. The user downloads the new installer and installs it.

Inspecting the UDIDs in an Installer

After an iOS installer (.ipa) is uploaded to Pgyer, the platform parses the provisioning profile and shows the list of UDIDs it contains on the app management page.