Toolstia / Chmod calculator
Chmod permission calculator
Tick the permissions for the owner, the group and everyone else, and get the three-digit chmod number, the rwx text form and a ready-to-use command. Or type a number such as 755 and see what it means.
| Who | Read (4) | Write (2) | Execute (1) |
|---|---|---|---|
| Owner (user) | |||
| Group | |||
| Others |
rw-r--r--
chmod 644 filename
Owner: read, write. Group: read. Others: read.
How it works
- Tick the permissions, or type the octal number.
- Check the explanation in plain words.
- Copy the chmod command.
How the number is built
Read counts as 4, write as 2 and execute as 1. Add them up for each of the three groups. So read and write is 6, and read, write and execute is 7. The digits are in the order owner, group, others.
Common settings
644 suits normal files: the owner can edit, others can read. 755 suits folders and programs. 600 and 700 keep things private to the owner. 777 lets everyone do everything and is rarely a good idea.
Folders need execute
On a folder, the execute permission means permission to open it and reach the files inside. A folder without it cannot be used even if it can be read.
Not covered
Special bits such as setuid, setgid and the sticky bit, which use a fourth digit, are not included here.
Questions
What does chmod 755 mean?
The owner can read, write and run. The group and others can read and run but not change.
Is 777 safe on a web server?
No. It lets any account on the machine change the file, which is a common security problem.
Can I apply it to every file in a folder?
Add the -R option to the command, but be careful, as folders and files usually need different settings.
Is anything uploaded?
No. Everything stays in your browser and is never sent anywhere.