FIRMWARE DETAILS

iOS 17.2.1

Build: 21C66Dec 19, 2023Delta OTA

Stable

View details

Filename: f01ba04421bd7842dad3794333187cb99d3f2bdc.zip
File size: 3.69 GB
File type: Delta OTA
Download host: updates.cdn-apple.com
Link availability: Not verified
Source reports active
Last link check: Not checked
SHA-256: 8a62782fccf2d3c0fe7cba2fbe4819170172b69ee627301828c3a941d927c224
SHA-1: 16a39a619d24009e9059e081602804996e24b2d2
Required starting builds: 20G75, 20G81, 20H19, 20H30
Board restrictions: Not reported

OTA packages can require an exact starting build and board. A matching hardware identifier alone is not sufficient for installation.

Compatible hardware (1)

iPhone XS iPhone11,2

Unknown

Signing is specific to the device and file. A signed build does not guarantee a downgrade or successful installation.

Source provenance

AppleDBhttps://api.appledb.dev/ios/iOS%3B21C66.json ↗

MIT — copyright 2022 emiyl
Last imported: Oct 19, 2026, 6:28 PM UTC
Record fingerprint: d446c7f095cdf40f999162af3ba1751c