FIRMWARE DETAILS

iOS 17.3.1

Build: 21D61Feb 8, 2024Delta OTA

Stable

View details

Filename: 74d4f45ddaadf6c401b2552d3d913aa7578e3fc6.zip
File size: 4.51 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: 1ef28ccf8d78368dc70765a63e0691dcc4be9487056cec2dd1901148e8f0e746
SHA-1: a7426fb9fb9d402a738f1647cdb437a21b1ea4b7
Required starting builds: 19A340, 19A344, 19A346, 19A348, 19A404
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