FIRMWARE DETAILS

iOS 17.5.1

Build: 21F90May 20, 2024Delta OTA

Stable

View details

Filename: 19fbadad1b0be3d72c0ce415c8666d85b925fdea.zip
File size: 2.21 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: 45f5e3bef25a317fad7ff490a2a2a7aefac5607ddb01caea37adfdb0337e4b0a
SHA-1: 1ec4f3856d17e4adf83182bd36363118d53d340b
Required starting builds: 21A326, 21A329, 21A360
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 13 iPhone14,5

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