FIRMWARE DETAILS

iOS 17.2.1

Build: 21C66Dec 19, 2023Delta OTA

Stable

View details

Filename: f91f2a5575d3daaf660d9e7895d51bc0a23f5527.zip
File size: 3.76 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: e0d97a6499223ae0da4a04b5ec824c5f64f0997eec0cd9b6734261474624c1c0
SHA-1: cc991acf7e5fbc5f0c8eaa6e263c2184f3324bda
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 XS Max iPhone11,6

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