Chmod Calculator
Developer ToolsNumeric / 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.