Does John the Ripper use GPU?

Yes, John the Ripper can use GPU, but standard John the Ripper core version primarily uses CPU, while John the Ripper jumbo version supports GPU acceleration through OpenCL. John the Ripper, abbreviated JTR, is a popular open-source password cracking tool originally designed for CPU-based cracking. The original core version, John the Ripper core, is CPU-only and optimized for fast CPU cracking of many hash types. However, the community-enhanced version called John the Ripper jumbo, also known as John the Ripper 1.9.0-jumbo-1, includes support for GPU acceleration using OpenCL, which allows it to use AMD, NVIDIA, and Intel GPUs to speed up cracking of certain hash types like NTLM, WPA, and others. There is also a separate branch called John the Ripper with OpenCL support that can utilize GPU. Performance gains from GPU can be 10 to 100 times faster than CPU for some hashes, though not all hash types benefit equally. For GPU cracking, you need OpenCL drivers installed and compatible GPU. Many users prefer Hashcat for pure GPU cracking as it is faster for GPU, while John the Ripper is better for CPU and diverse hash types. So yes, John the Ripper can use GPU through jumbo version with OpenCL, but default core version is CPU-only, and you need to compile with OpenCL support to enable GPU.