About This Firmware
iOS 4.0.2
(build 8A400) is an official Apple IPSW
for the iPhone 3GS.
The download is 377.95 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_4.0.2_8A400_Restore.ipsw
Checksums
SHA-256
96268657372f6209ec0ea3c629f493a4dfd7bc7ce10506af86bdad54b09dd06a
SHA-1
61d21363ced6e006cc226f9a0a0e9c6ed8e048ab
MD5
9cb5684457fb41886827d727d91313c3
Direct URL
https://secure-appldnld.apple.com/iPhone4/061-8805.20100811.Dcr4e/iPhone2,1_4.0.2_8A400_Restore.ipsw
Other Devices
iPhone 16 Plus
iPhone17,4
iPhone 14
iPhone14,7
iPhone 5 (Global)
iPhone5,2
iPhone X (Global)
iPhone10,3
iPhone 12 Pro
iPhone13,3
iPhone SE (2020)
iPhone12,8
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