FIRMWARE DETAILS

iOS 17.2.1

Build: 21C66Dec 19, 2023Delta OTA

Stable

View details

Filename: f70b9c7c15c1d7cdc9ffcca831b8ecc8339c3b29.zip
File size: 1.14 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: bfb13f93d7ae71eeab38bf3188b9eeb0782ac90f7445f4904de390aa46977d42
SHA-1: 78c02d8679722aa20fdbdd947ec9d00571d4567d
Required starting builds: 21B101, 21B74, 21B91
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