FIRMWARE DETAILS

iOS 17.5.1

Build: 21F90May 20, 2024Full OTA

Stable

View details

Filename: 51aef431d8c7c208d478a5c86b24aa8c9f2435d8.zip
File size: 5.91 GB
File type: Full OTA
Download host: updates.cdn-apple.com
Link availability: Not verified
Source reports active
Last link check: Not checked
SHA-256: 88fc9ac6e1cd7902e9b8471a0731e4512e9c0ab93f51d11eaee734fe5490ec13
SHA-1: 40a99c7fd9765184ecf3f4fd20e05fb3b1f2e3dd
Required starting builds: Not reported
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 XR iPhone11,8

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%3B21F90.json ↗

MIT — copyright 2022 emiyl
Last imported: Oct 19, 2026, 6:28 PM UTC
Record fingerprint: 1ae039bd01274135bfccfb7ce06a0234