John the Ripper
John the Ripper (JtR) is an open-source password security auditing and recovery tool. It supports hundreds of hash and cipher types — from Unix crypt to Windows NTLM, from PDF and Office documents to ZIP and RAR archives — and combines multiple cracking modes with powerful rule-based wordlist mutations.
John is the standard tool for password cracking in cybersecurity assessments, penetration tests, and CTF challenges. Its Jumbo variant includes GPU acceleration via OpenCL and a vast library of format modules.
Module Sections
Installation
Install John the Ripper on Linux, macOS, Windows, or build from source with Jumbo patches.
Single Crack Mode
Uses login name, GECOS, and full name fields to generate candidate passwords. Fast and often surprisingly effective.
Wordlist Mode
Tries passwords from a wordlist file. The most common cracking method, enhanced with rules for mutations.
Incremental / Brute Force
Generates all possible character combinations. Slowest but most thorough method for short passwords.
External Mode
Plug in custom password generation logic written in a C-like scripting language. For advanced attack scenarios.
Hash Formats
Comprehensive reference of supported hash types: Unix crypts, Windows NTLM, documents, archives, and more.
Rules
Mutate wordlist entries with case changes, leet speak, appending/prepending, and thousands of transformations.
Hash Extraction
Extract password hashes from files: zip2john, rar2john, pdf2john, ssh2john, keepass2john, and more.
Command Builder
Interactive tool to select options, configure sessions, and generate optimized John commands.
Examples
Real-world cracking scenarios and the exact commands for each situation.
Pro Tips
Expert advice on session management, performance tuning, format-specific optimization, and brute forcing strategies.
John the Ripper Quiz
Test your password cracking knowledge with 20 multiple-choice questions covering modes, formats, and usage.
John the Ripper Lab
Hands-on exercises where you write John commands to crack different hash types using various modes and options.
Quick Start
New to John the Ripper? Start with these three sections in order:
Info