FIRMWARE DETAILS

iOS 17.1

Build: 21B74Oct 25, 2023Delta OTA

Release CandidateStable

View details

Filename: 8fbb655df954639cba2fb0455e9eb85f6d7141cc.zip
File size: 3.54 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: 2e405b49c9b0f400ec370c78872a8a0e77a22affc74aed3208717b2160382c7d
SHA-1: ea76b35111114282719918a906b76f977d5f19fe
Required starting builds: 20G75, 20G81, 20H19, 20H30
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