IPSW Downloads

iOS 4.2.1 - 8C148 for iPhone 4

This firmware is not signed. This means you cannot restore to it in iTunes.

Release DateInvalid Date
Upload Date18 November 2010
File NameiPhone3,1_4.2.1_8C148_Restore.ipsw
File Size0.61 GB
SHA256sum
MD5sum93957e7bd21f0549b60a60485c13206a
SHA1sumb8b485c111fc25515487dbada0f2e630b66ccdb1
IdentifieriPhone3,1

Installation Instructions

Windows

  1. Install the latest version of iTunes from the Microsoft Store.
  2. Connect your iPhone 4 to your PC.
  3. Open iTunes and navigate to your iPhone 4.
  4. Hold the Shift key and click "Restore".
  5. Select the iPhone3,1_4.2.1_8C148_Restore.ipsw file you downloaded.
  6. Wait for the restore to complete and for your iPhone 4 to reboot.

macOS

  1. Connect your iPhone 4 to your Mac.
  2. Navigate to your iPhone 4 in Finder.
  3. Hold the Option or Alt key and click "Restore".
  4. Select the iPhone3,1_4.2.1_8C148_Restore.ipsw file you downloaded.
  5. Wait for the restore to complete and for your iPhone 4 to reboot.

Linux

  1. Install idevicerestore.
  2. Connect your iPhone 4 to your PC.
  3. Open a terminal and navigate to the IPSW file you downloaded, e.g., cd ~/Downloads.
  4. To perform a full erase restore, type idevicerestore -e iPhone3,1_4.2.1_8C148_Restore.ipsw and press Enter.
  5. Wait for the restore to complete and for your iPhone 4 to reboot.