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FIRMWARE DETAILS

iOS 17.5.1

Build: 21F90May 20, 2024Delta OTA
Stable

View details

Filename
b5c42f5a6146526eb9fc123971b346a6e404287f.zip
File size
1.76 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
903bff3977930d98e54ec000ec0a4ed8e403a19e1c772ac17393322ed08e2859
SHA-1
dbd6094febb4d7feeb12114a8b6622d5f5557455
Required starting builds
21C62, 21C66
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