What's my iPhone's UDID?
Open this page on the iPhone or iPad, tap the button, and your UDID appears here. No Mac, no cable.
How it works
Safari can't read a device's UDID, so the button downloads a small Apple configuration profile. When you install it, iOS sends the UDID to us and we send you straight back to this page with it. The profile installs nothing else, and you can remove it right after.
Sending a build to testers? Upload the IPA and App Dropper collects their UDIDs for you. The full routine is in iOS UDIDs for ad hoc builds.
Questions
Why does a developer want my UDID?
Test builds that aren't on the App Store only install on devices Apple knows about. The developer registers your UDID with Apple, builds again, and the app installs on your phone.
Why does iOS say the profile is Not Verified?
The profile isn't signed with a certificate yet, so iOS can't vouch for who made it. It installs nothing and changes no settings. It only asks your device for its UDID, model and iOS version, then sends you back here.
Do you keep my UDID?
No. The values travel back to this page in the link and are shown to you. Nothing is written on our side.
Can I delete the profile afterwards?
Yes, and you should. Settings, General, VPN & Device Management, then remove the App Dropper profile.
What does a UDID look like?
On an iPhone XS or newer it is 25 characters like 00008110-001A2B3C4D5E801E. On older devices it is 40 letters and numbers. Serial numbers and IMEIs are different things.
I'm the developer. Can I collect UDIDs from my testers this way?
Yes. Every app on App Dropper has a register-this-iPhone link. Testers tap it, their device lands in your Devices tab, and you export the list in the format the Apple Developer portal takes.