Click checkboxes to set permissions for owner, group, and others. The octal number and symbolic notation update in real time. You can also type an octal number directly in the input fields. Click “Copy” to copy the chmod command.
Every file and directory in Linux has three permission levels: Owner (the file creator), Group (users in the file's group), and Others (everyone else). Each level can have Read (view contents), Write (modify), and Execute (run/enter directory) permissions.
0 | --- | No permissions |
1 | --x | Execute only |
2 | -w- | Write only |
3 | -wx | Write + Execute |
4 | r-- | Read only |
5 | r-x | Read + Execute |
6 | rw- | Read + Write |
7 | rwx | Read + Write + Execute |
chmod 755 file | Owner: full, Group/Others: read+execute (typical for scripts/dirs) |
chmod 644 file | Owner: read+write, Group/Others: read (typical for files) |
chmod 600 file | Owner: read+write, no access for others (private) |
chmod 400 key | Owner: read only (SSH private keys) |
chmod -R 755 dir/ | Apply recursively to directory and contents |