How to get Device UDID without XCode and without downloading any profile in 2020

Question

What is the best way/ right way to get the device's UDID? Without having XCode or without downloading any profile.
I've tried get.udid.io - It isn't working for my iPad, though worked for iPhone. I've tried whatsmyudid.com - It downloads a profile which is not verified- Can't ask my client to download such profiles.
Moreover, what is the official way of knowing my device's UDID?

Answer 1

You can get device UDID by connecting it to Mac and run following command on terminal.

instruments -s devices

instruments is deprecated now use rcrun

xcrun xctrace list devices

It will display all devices names (and simulators) along with UDID.