iPhone and iPod Touch Compatibility With iOS 4.0
- iPhone 3GS: Full iOS 4.0 compatible except iPhone 4 specific features
- iPhone 3G: Partial iOS 4.0 support. Doesn’t support multitasking, wallpaper and Bluetooth keyboard.
- iPhone 2G: No iOS 4.0 support. (Custom Modded 3.1.3 with iOS 4 features available)
- iPod Touch 3G: Full iOS 4.0 support except for iPhone specific features
- iPod Touch 2G: Partial iOS 4.0 support. Doesn’t support multitasking, wallpaper and Bluetooth keyboard.
- iPod Touch 1G: No iOS 4.0 support.
Once you have found your iPhone or iPod touch model and decided to upgrade to iOS 4 Firmware, you need to update your iTunes to 9.2 if you haven’t done it already. Only the latest iTunes 9.2 supports iOS 4.0. Also don’t forget to take a backup of your data before upgrading to iOS 4 Firmware.
If you rely on Jailbreak or Unlock, then do not upgrade to iOS 4.0, until you hear from the iPhone Dev team.