Chmod Calculator
Numeric / Symbolic
How to use this chmod calculator
- Check the read/write/execute boxes for Owner, Group, and Others.
- The numeric code (like 755) and the ready-to-use command update instantly.
- Copy the command and run it in your terminal.
How do Unix file permissions work?
Every file has three permission sets — for the owner, the group, and everyone else — each with read (4), write (2), and execute (1) bits. Adding those numbers gives the digit for that group, so 755 means the owner can read/write/execute, while group and others can only read/execute.
What does 777 mean, and why is it usually a bad idea?
777 gives everyone full read, write and execute access. It's convenient for testing but a serious security risk on real servers, since it lets any user modify or run the file.
What's a typical safe permission for a website file?
644 for regular files (owner can read/write, everyone else read-only) and 755 for directories and scripts that need to be executed are common, secure defaults.