FIRMWARE DETAILS

iOS 17.2.1

Build: 21C66Dec 19, 2023Delta OTA

Stable

View details

Filename: efa6a7369d02d18ea54fd27116aa689122ef706a.zip
File size: 3.72 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: b33a52df1788dbdd1da26eb3352261e4c97a4c2fe46b31730a0bb9b6d15009ad
SHA-1: 9464bdbf89c3c291b33c351a7f6866334cde0744
Required starting builds: 20C65, 20D47, 20D67
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 XR iPhone11,8

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