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FIRMWARE DETAILS

iOS 17.3.1

Build: 21D61Feb 8, 2024Delta OTA
Stable

View details

Filename
a990bd235f4a1bc0c9e13cd54c5701620c458f2a.zip
File size
3.51 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
d691551cf9892f41e2c6a105bfe110266a05619469f5b623ee1dcb5c50c38395
SHA-1
ff9c2282dfc191c8f32ba5e30b6340ed1e8ae9ef
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%3B21D61.json ↗

MIT — copyright 2022 emiyl
Last imported: Oct 19, 2026, 6:28 PM UTC
Record fingerprint: caa4c3b8f1108221a1cf4826799a13ca