FIRMWARE DETAILS

iOS 17.3.1

Build: 21D61Feb 8, 2024Delta OTA

Stable

View details

Filename: 5b78f55f65bd099ac6a4477676c3ba92f31fef3a.zip
File size: 3.46 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: b711264da09c7b038b77fbfa9f54b499edbc7fba05e41aba55af86411d738b71
SHA-1: b3b780e0c1d0570356d0f9c48c0634e9444ef597
Required starting builds: 20E247, 20E252
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 12 iPhone13,2

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