
Free
About
Stop guessing Linux file permissions. CHMOD Lab is the ultimate interactive sandbox and calculator for developers, SysAdmins, and students who want to master the command line.
Whether you are configuring a web server, debugging a script, or studying for your Linux certification, CHMOD Lab bridges the gap between confusing octal numbers (755) and symbolic notation (rwxr-xr-x).
FEATURES:
• Interactive Calculator: Toggle permissions instantly. Tap "Read," "Write," or "Execute" and watch the Octal and Symbolic codes update in real-time.
• Reverse Lookup: Type in a code like "644" and see exactly which permissions are granted.
• Visual Sandbox: See permissions visualized to understand "who" can do "what" before you run the command.
• Cheat Sheet: Built-in reference guides for common permission patterns.
Master the command line. Download CHMOD Lab today.
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What's New in CHMOD Lab
1.0
January 6, 2026









