Unix Chmod Permission Calculator
Unix permissions
Chmod Calculator
Convert file permission checkboxes into chmod octal and symbolic notation.
Owner
Group
Other
Usage guide
Translate Unix permission bits into octal and symbolic chmod values
Unix file permissions combine read, write, and execute bits for the owner, group, and others. A chmod calculator helps visualize the permission mask before you apply it to files or directories.
How to use Chmod Calculator
- 1.Select read, write, and execute permissions separately for owner, group, and others.
- 2.Compare the resulting symbolic form with the three-digit octal value.
- 3.Apply the permission only after checking whether the file is a regular file, script, directory, or sensitive credential.
Examples
- 755 gives the owner read/write/execute and gives group and others read/execute.
- 644 is common for ordinary non-executable files because only the owner can write.
- 600 restricts a sensitive file to owner read/write with no permissions for group or others.
Limitations and notes
- The safest permission depends on the application, ownership, server configuration, and whether the path is a file or directory.
- Do not use broad permissions such as 777 merely to bypass a deployment problem without understanding the security impact.
What does chmod 755 mean?
The owner gets rwx permissions, while group and others get r-x. In octal, 7 is 4+2+1 and 5 is 4+1.
Why can directories need execute permission?
For directories, execute permission controls traversal and access to entries, so its meaning differs from executing a program file.
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How the chmod calculator works
Paste or enter the code, data, or value you want to inspect.
The tool processes it locally in your browser.
Copy the formatted output or converted value for your project.
Frequently Asked Questions
Is the chmod calculator free?
Yes. It is free and does not require an account.
Is my code sent to a server?
No. These developer tools run locally in your browser.
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