FIRMWARE DETAILS

iOS 17.1

Build: 21B74Oct 25, 2023Delta OTA

Release CandidateStable

View details

Filename: 91929a4174ced34490bd850f9827adb99615cfd2.zip
File size: 916.1 MB
File type: Delta OTA
Download host: updates.cdn-apple.com
Link availability: Not verified
Source reports active
Last link check: Not checked
SHA-256: 8866b6080e813f8b9ec896f89d1d8ecaeefd18a87c979f3a0c91393986ecedd5
SHA-1: e38211b2e9ee10c0f3f669fa7a2d0ec19cfc0965
Required starting builds: 21A340, 21A351
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%3B21B74.json ↗

MIT — copyright 2022 emiyl
Last imported: Oct 19, 2026, 6:28 PM UTC
Record fingerprint: ce1037df7218db6f4121eac6e89afc29