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FIRMWARE DETAILS

iOS 17.5.1

Build: 21F90May 20, 2024Delta OTA
Stable

View details

Filename
3f941c51dbfe9cffda58b5c4e6d1f06ea0090377.zip
File size
4.20 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
857e198fa5f6029398f71a7ce9b5348a9d228b335d4dc69d3765f9dca42fef37
SHA-1
115bf5c0c88d73242f01897de06429e250c4abff
Required starting builds
20B101, 20B110, 20B82
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)

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