FIRMWARE DETAILS

iOS 17.3.1

Build: 21D61Feb 8, 2024Delta OTA

Stable

View details

Filename: b50aec2c9c0510f7e9649e5af9798b874ab21488.zip
File size: 1.16 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: 1a775df6474f16261038e80bdcd46d5fc150e8783fb06b76fba39cdcdeef353b
SHA-1: 6336b232110d578661d1212c9a20fe8b25f3681c
Required starting builds: 21B101, 21B74, 21B91
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