FIRMWARE DETAILS

iOS 17.1.1

Build: 21B91Nov 8, 2023Delta OTA

Stable

View details

Filename: 56e9bc809678977624040e4df261cb734470825d.zip
File size: 4.79 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: 5c3dc10a4769b804dd0f319a55ec497a62655656f1d95fa2f94be7cdf3a14d24
SHA-1: 0dfdbbc0f3e951806e10198eb1acc225a128f8e0
Required starting builds: 18E199, 18E212, 18F72
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 11 iPhone12,1

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%3B21B91.json ↗

MIT — copyright 2022 emiyl
Last imported: Oct 19, 2026, 6:28 PM UTC
Record fingerprint: 920b0a70bb6d0ccadee92018f5db3f40