iPhone 11 iPhone12,1

IPSW Unsigned 21C66

iOS 17.2.1

iOS

Version

17.2.1

Build ID

21C66

File Size

6.81 GB

Release Date

2023-12-19

Last Updated

2023-12-16

Download IPSW

Beta firmware? Download Here →

Want full hardware specs? View iPhone 11 specs →

About This Firmware

iOS 17.2.1 (build 21C66) is an official Apple IPSW for the iPhone 11, released on 2023-12-19. The file 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 SHA-256 or SHA-1 checksum listed in the Checksums section below.

Filename

iPhone12,1_17.2.1_21C66_Restore.ipsw

Checksums

SHA-256 ff373763bb1fe50fb7a19a7f1084c217336a173da9a27afcb72092f13858e937

SHA-1 658e5a63e1adedcb43a2672f26f0b1751be55fff

MD5 6d68561cb7574f7b9d618b6fdd18697b

Direct URL

https://updates.cdn-apple.com/2023FallFCS/fullrestores/052-16061/C5B166A1-BA91-40BD-875E-EA889F68624F/iPhone12,1_17.2.1_21C66_Restore.ipsw

Other Devices

iPhone XS Max (China)

iPhone11,4

iPhone 8 Plus (Global)

How to Restore with This IPSW

iTunes / Finder

macOS & Windows

Download the .ipsw file to your computer.
Connect your iPhone 11 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 11 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 tip

If 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