Redsn0w Ios 15 ((link))

Instead, check your iOS version:

Redsn0w cannot recognize or exploit any version of iOS 15. Attempting to use it on a modern device will result in "unsupported firmware" errors or potential device instability. Modern Alternatives for iOS 15 Redsn0w Ios 15

For users on the cusp of iOS 15 (those on iOS 14.6 through 14.8), tools like (by Pwn20wnd) and Taurine (by CoolStar/Odyssey Team) were the successors to the legacy of Redsn0w. Instead, check your iOS version: Redsn0w cannot recognize

Settings > General > About > Software Version. Redsn0w Ios 15

Redsn0w was a jailbreak tool for older iOS versions (iOS 4.x to 6.x, and limited support for iOS 9.x tethered). It has not been updated since 2013 and will not work on any device running iOS 15.