FIRMWARE DETAILS

iOS 17.5.1

Build: 21F90May 20, 2024Delta OTA

Stable

View details

Filename: c1f716bb314069eae16546f7b7fd2bb57cbe0db4.zip
File size: 1.98 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: 024727d0fe37d46e9358be023e88820281b3600cb6c165d5c70a03073ed37abd
SHA-1: aafb031c892f4dc5284014062783cbc6b7fb9723
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 XS Max iPhone11,6

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