How to find an iPhone's UDID

This tutorial will show a simple way to find this information without any app, certificate installs nor iTunes.

This tutorial requires only a macOS device, the iPhone and the phone's power cord. If you have the iPhone paired to the macOS device through wi-fi, you don't need a power cord and can skip steps 1 and 2. This tutorial was based on macOS Ventura and it applies on older versions of macOS as well.

Steps

1. Connect the iPhone to an USB port of your macOS device.
2. If the iPhone asks for permission to trust the macOS device, grant it (assuming it's a device you trust).
3. Open the Finder app.
4. Go to the iPhone in the Locations section of the sidebar. It should open the device's page.
5. Click on the info section bellow the iPhone name on the top of the page until it displays the UDID.

The iPhone’s page on Finder with an arrow pointing to the section where the UDID is.

You can copy the UDID by right clicking on it.