About This Firmware
iOS 4.3.4
(build 8K2) is an official Apple IPSW
for the iPhone 3GS.
The download is 420.15 MB and is served directly from Apple's CDN.
This firmware is no longer signed by Apple. Standard downgrades are not possible, but the file remains available for reference and advanced use.
Verify the download using the checksums below.
Filename
iPhone2,1_4.3.4_8K2_Restore.ipsw
Checksums
SHA-256
f516f1b5ac2111ca8b81ffa6e9b3867d74cf28c84100a2cf3baea0842a31b1cb
SHA-1
be06903d55dc13d8948ae4cfa619a277df4d4e5b
MD5
a172829312329d3bda87d23abf5ec4d4
Direct URL
https://secure-appldnld.apple.com/iPhone4/041-1921.20110715.ItuLh/iPhone2,1_4.3.4_8K2_Restore.ipsw
Other Devices
iPhone 5 (GSM)
iPhone5,1
iPhone 3G
iPhone1,2
iPhone 5 (Global)
iPhone5,2
iPhone 6+
iPhone7,1
iPhone Air
iPhone18,4
iPhone 14 Pro
iPhone15,2
How to Restore with This IPSW
iTunes / Finder
macOS & Windows- Download the .ipsw file to your computer.
- Connect your iPhone 3GS via USB.
- Open iTunes (Windows / macOS Mojave and earlier) or Finder (macOS Catalina+) and select your device.
- Update (keep data): hold Option (Mac) or Shift (Windows) and click Update, then pick the .ipsw file.
- Restore (erase & install): hold Option / Shift and click Restore iPhone…, then pick the .ipsw file.
- Wait for the process to finish - do not disconnect.
Restoring will erase all data on the device. Back up first.
3uTools
Windows- Download and install 3uTools from 3u.com.
- Connect your iPhone 3GS via USB and trust the computer on the device.
- Go to Flash & JB > Easy Flash.
- Click Import and select the downloaded .ipsw file.
- Choose Flash mode: Update keeps data, Restore wipes the device.
- Click Flash and wait for the progress bar to complete - do not disconnect.
Only flash firmware that matches your exact device model.
DFU Mode
Recovery tipIf your device is stuck in a boot loop or iTunes/Finder does not recognise it, enter DFU mode first, then select the .ipsw file as normal.
iPhone 8 / X and later
- Quickly press & release Volume Up
- Quickly press & release Volume Down
- Hold Side button until screen goes black
- Hold Side + Volume Down for 5 s
- Release Side, hold Volume Down 5 more s
- Black screen = DFU active
iPhone 7 / 7 Plus
- Hold Sleep/Wake + Volume Down for 8 s
- Release Sleep/Wake, keep holding Volume Down for 5 s
- Black screen = DFU active
iPhone 6s and earlier
- Hold Sleep/Wake + Home for 8 s
- Release Sleep/Wake, keep holding Home for 5 s
- Black screen = DFU active