FIRMWARE DETAILS

iOS 17.5.1

Build: 21F90May 20, 2024Delta OTA

Stable

View details

Filename: c1b0406ad26c69efa08d5a9f1bd03288d8f47ca9.zip
File size: 4.86 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: 2a0cb6437f0c412e96eb214665bab816ca0c028a8095027721f30792d4a30cae
SHA-1: b10d4d880c53efb28d1a7d64d3949ba20f7346b6
Required starting builds: 18G69, 18G82, 18H107, 18H17
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 SE (2nd generation) iPhone12,8

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%3B21F90.json ↗

MIT — copyright 2022 emiyl
Last imported: Oct 19, 2026, 6:28 PM UTC
Record fingerprint: 1ae039bd01274135bfccfb7ce06a0234