Linux permission calculator

Visualize file permissions, convert octal values, and generate chmod commands without memorizing every bit.

Octal code
Examples: 755, 644
Symbolic mode
-rwxr-xr-x
chmod 755 filename
Owner
Group
Public

How Linux permissions work

4
Read (r)
Allows viewing a file or listing a directory.
2
Write (w)
Allows editing a file or creating and removing items in a directory.
1
Execute (x)
Allows running a file or entering a directory.
Permission groups
Owner
The user who owns the file or directory.
Group
Users in the file's assigned group.
Public
Everyone else outside the owner and group.

Frequently asked questions

What does chmod 777 mean?

chmod 777 grants read, write, and execute permissions to everyone. It is extremely permissive and is usually unsafe for production systems unless you understand the security tradeoff.

What permissions should website files usually use?

A common baseline is 755 for directories, 644 for regular files, and 600 for sensitive config files that should only be readable by the owner.