checkra1n

checkra1n provides a semi‑tethered jailbreak for iPhone models from the 5s through the X, supporting iOS versions 12.0 and higher. The tool runs on macOS and Linux, with beta releases that include fixes for A9X devices and guidance for A11 devices on newer iOS releases. Users must connect the iPhone to a computer, place it in DFU mode, and let the application perform the exploit, after which the device boots in a jailbroken state until the next reboot.

The jailbreak is based on the checkm8 bootrom exploit, allowing installation of the Cydia package manager and, in future releases, additional managers such as Zebra and Installer. Because it is semi‑tethered, the device returns to stock iOS after a reboot unless the checkra1n process is run again. The project maintains a community‑driven development model, offering beta previews and documentation for supported hardware and operating systems.

Target users are owners of supported iPhone models who wish to run unsigned code or third‑party software not approved by Apple. The software is distributed as a downloadable binary for macOS and Linux, with ongoing work to add Windows support and to address known issues on certain devices and language settings.