Calculate Unix file permissions interactively — click checkboxes to get numeric and symbolic chmod values.
Developer Tools
Tool
Read
Write
Execute
Octal
Owner
6
Group
4
Other
4
Numeric
644
Symbolic
-rw-r--r--
Command
chmod 644 filename
How to Use
1Check or uncheck Read, Write, and Execute permissions for Owner, Group, and Other
2Or type a numeric mode (e.g., 755) in the text field
3The numeric mode, symbolic notation, and chmod command update instantly
4Copy the chmod command to use in your terminal
Frequently Asked Questions
chmod (change mode) is a Unix/Linux command used to change the access permissions of files and directories. Permissions define who can read, write, or execute a file.
Each permission group (owner, group, other) is assigned a number: Read=4, Write=2, Execute=1. Add the values for each group. For example, rwx=7, r-x=5, r--=4, giving 754.
755 means the owner can read, write, and execute (7=4+2+1), while group members and others can only read and execute (5=4+1). This is common for web server files.
Symbolic notation uses letters: r (read), w (write), x (execute), - (no permission). For example, -rwxr-xr-x represents a file (not directory) with mode 755.