FIRMWARE DETAILS

iOS 17.3.1

Build: 21D61Feb 8, 2024Delta OTA

Stable

View details

Filename: 48f014095d8a6ba5fa135155ea44e49b03150fba.zip
File size: 3.73 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: 1aad420dc253a590bddf86b6a668f4c2f549f19ffad39e7e2ca7391ceb6422ce
SHA-1: 2da69144047e7ff71bcd93587e18571e6226f9b5
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)

iPhone XS iPhone11,2

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