Chmod Calculator
Calculate Unix file permissions in octal and symbolic notation with a chmod command. Free online tool with visual toggles, no signup.
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Frequently asked questions
- What does chmod 755 mean?
- 755 grants the owner read, write, and execute permissions (7), while the group and others get only read and execute (5). It is the standard permission for executable scripts and public directories.
- What is the difference between octal and symbolic notation?
- Octal notation uses three digits (e.g. 755) where each digit sums read (4), write (2), and execute (1). Symbolic notation uses nine characters (e.g. rwxr-xr-x) showing each permission explicitly for owner, group, and other.
- What is a safe permission for sensitive files?
- Use 600 for private files like SSH keys and config files with secrets. Only the owner can read or write, and no one else has any access.
- Can I type the octal value instead of ticking boxes?
- Yes. Entering three digits from 0 to 7 moves the checkboxes, and the checkboxes update the number, so you can work from either direction. The matching chmod command is shown ready to copy.
- Does it cover setuid, setgid, and the sticky bit?
- No. Only the three-digit owner, group, and other form is supported. Those special bits live in a leading fourth digit that this calculator does not produce.