iOS 4.2.1 (8C148)
iPhone 3G
Other Signed iOS Versions
How to Restore iOS 4.2.1 IPSW
🖥
iTunes (Windows / macOS Mojave and older) & Finder (macOS Catalina+)
- Download the iPhone1,2_4.2.1_8C148_Restore.ipsw file to your computer.
- Connect your iPhone 3G to your computer with a USB cable.
- Open Finder (macOS Catalina+) or iTunes (Windows / older macOS) and select your device.
- To Update (keeps data): hold Option (Mac) or Shift (Windows) and click Check for Update.
- To Restore (erases data): hold Option (Mac) or Shift (Windows) and click Restore iPhone/iPad.
- Navigate to and select the downloaded .ipsw file, then confirm.
- Wait for the process to complete — do not disconnect the device.
⌨️
idevicerestore (Command Line)
An open-source command-line tool that restores IPSW files without needing iTunes. Useful for advanced users, automation, and custom restore workflows.
- Install via Homebrew:
brew install idevicerestore
- Connect your device and put it into DFU mode.
- Run the restore command:
idevicerestore -t iPhone1,2_4.2.1_8C148_Restore.ipsw
Common flags:
-eErase restore (factory reset)
-uUpdate restore (keep data)
-dEnable debug output
-nDry-run — don't actually restore
🔓
futurerestore (Saved Blobs / Downgrade)
futurerestore allows restoring to any firmware when you have saved APTickets (blobs) from a tool like TSSSaver or shsh.host.
- Download futurerestore from github.com/futurerestore/futurerestore.
- Ensure you have a saved .shsh2 blob for iOS 4.2.1 (8C148) on your iPhone 3G.
- Put your device into DFU mode and run:
futurerestore -t your_blob.shsh2 --latest-sep --latest-baseband iPhone1,2_4.2.1_8C148_Restore.ipsw
⛔ Warning: Using --latest-sep requires the latest SEP to be compatible with iOS 4.2.1. Always verify compatibility before restoring to avoid a bricked device.
📲
Entering DFU Mode
DFU (Device Firmware Update) mode is required for most manual restores. The button combination varies by device:
iPhone 8 / X and later / iPad with Face ID
Press & release Volume Up → press & release Volume Down → hold Side button until screen goes black → hold Side + Volume Down for 5 s → release Side but keep Volume Down for 10 s.
iPhone 7 / 7 Plus
Hold Side + Volume Down for 8 s → release Side but keep Volume Down for 10 s.
iPhone 6s and earlier / iPad with Home button
Hold Home + Sleep/Wake for 8 s → release Sleep/Wake but keep Home for 10 s.
💡 Tip: In DFU mode the screen stays completely black. If you see the Apple logo or a "Connect to iTunes" screen, you entered Recovery mode instead — try again.
iPhone1,2_4.2.1_8C148_Restore.ipsw
SHA1
d2ed58586e8ca2153f2e2ec585bba8afc5173378
SHA256
98e5969c3baed660c9a26e94cd7ed4b3cdb7175900f448bcc2223bf885835ce0
MD5
8b1657935408a1638b69740b282f62b3
⇓ Download IPSW (0.32 GB)
