You can install iOS and/or watchOS betas on your devices without needing an active Apple Developer account. This is achieved via signed Profile Certificates that allow your device(s) to receive the OTA update (and to continue receiving them once the profile is installed).
- iOS 12.0 Developer Beta 2
- watchOS 5.0 Developer Beta 2
- Download the iOS 12 beta profile (scan) on your iOS device.
- Click "Install" in the top right.
- Agree to the terms/conditions.
- Once the profile is installed and your device reboots, to to Settings -> General -> Software Update.
- iOS 12 is only for 64-bit devices.
- When updating to iOS 12, from iOS 11 or lower, any backups you make of your device via iTunes or iCloud will NOT be usable if you downgrade to iOS 11 or lower. 32-bit applications do not work on iOS 12 betas. You will receive an error stating that the developer needs to update the application for iOS 12.
- Download the watchOS 5 beta profile (scan) to the iPhone paired to your Apple Watch
- Install the watchOS 5 beta profile
- Open the Watch app:
- My Watch -> General -> Software Update -> Download & Install Update
- Enter your passcode
- Agree to the terms/conditions
- Click Install
- Wait for the update to download and install
- Please remember that you cannot manually downgrade your Apple Watch from Watch OS 4 beta. You will need to send it into an Apple Service Center in order to get it downgraded. You can read up on how to do so here. You may also need to have the iOS 12 beta installed on your iPhone for the watchOS 5 beta to install properly.