firmwarehub.
العربية
FIRMWARE DETAILS

iOS 17.5.1

Build: 21F90May 20, 2024Delta OTA
Stable

View details

Filename
a449c2311ec2fd8a8b6e236bc9939846fdbff740.zip
File size
3.78 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
f7bf9e1d0c66733568511b3ea72a4501362734c8e8ae1fd4d4c45bcb0916ab3c
SHA-1
8b99d135dbc42594632fc6180b70f1a9dfccd87a
Required starting builds
20F66, 20F75
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