Chmod Calculator
Easily calculate Unix file permissions
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⚙️ How It Works
Simply check or uncheck the visually laid out Read, Write, and Execute checkboxes for each user class (Owner, Group, Public). As you click, the respective octal value and the precise terminal chmod command update in real-time.
❓ Frequently Asked Questions
What is chmod?
A Unix command to change file and directory permissions (read, write, execute) for owner, group, and others.
What does 755 mean?
Owner: rwx (7), Group: r-x (5), Others: r-x (5). Common for directories and executables.
What does 644 mean?
Owner: rw- (6), Group: r-- (4), Others: r-- (4). Typical for regular files.
Is 777 safe?
No. It grants full access to everyone. Avoid except for temporary debugging.
What do r, w, x stand for?
r = read, w = write, x = execute.
How are octal values calculated?
r=4, w=2, x=1. Add them per user class to get each digit.
What's the difference between files and directories?
Execute allows running files, but for directories it allows entering/traversing.
What does chmod +x do?
Adds execute permission without changing other existing permissions.
What is symbolic vs octal mode?
Symbolic uses letters (u+x), octal uses numbers (755).
What does 700 mean?
Owner: rwx (7), Group: --- (0), Others: --- (0). Fully private.
Does the Chmod Calculator work offline?
Yes, the Chmod Calculator is fully functional offline. Because this tool runs entirely in your browser, no data is ever uploaded to external servers. Once the page is loaded, you can seamlessly continue using it without an active internet connection. You can also install Knicknaks as a Progressive Web App (PWA) for native-like offline access.