BigForgeKit

Development

chmod Calculator

Convert Unix file permissions between octal and symbolic notation.

Octal permissions

Enter a three or four digit chmod value such as 755, 644 or 1777.

Visual permission editor

Toggle read, write and execute permissions for the owner, group and other users.

Owner

Permissions for the file or directory owner.

Group

Permissions for users in the assigned group.

Others

Permissions for every other user.

Special permission bits

Enable setuid, setgid or the sticky bit when the resource requires special Unix permission behavior.

Generated chmod

Inspect the octal and symbolic forms and generate a ready-to-use chmod command.

Octal

755

Symbolic

rwxr-xr-x
Command
chmod 755 path

Permission values

Each permission contributes a numeric value to the final chmod digit.

r4

Read

Allows reading files or listing directory contents.

w2

Write

Allows modifying files or directory contents.

x1

Execute

Allows executing files or entering directories.

Permission calculations run locally inside your browser. BigForgeKit does not access your files or execute chmod commands.

About this tool

What is chmod Calculator?

chmod Calculator converts Unix file and directory permissions between octal and symbolic notation. Configure read, write and execute permissions visually, enable special permission bits and generate a ready-to-use chmod command.

Features

Built for fast developer workflows

  • Convert octal permissions such as 755, 644 and 1777.
  • Generate symbolic permissions such as rwxr-xr-x.
  • Toggle read, write and execute permissions visually.
  • Configure owner, group and other user permissions.
  • Support setuid, setgid and the sticky bit.
  • Explain the numeric values of read, write and execute permissions.
  • Generate a complete chmod command for a file or directory.
  • Copy octal, symbolic and command results.
  • Load common Unix permission examples.
  • Perform every calculation locally in your browser.

Frequently asked questions

Questions about chmod Calculator

What does chmod 755 mean?

The owner can read, write and execute. The group and other users can read and execute, but cannot write.

What does chmod 644 mean?

The owner can read and write. The group and other users can only read.

What do the numbers 4, 2 and 1 represent?

Read has a value of 4, write has a value of 2 and execute has a value of 1. Adding them produces each permission digit.

What is the sticky bit?

On a shared directory, the sticky bit prevents users from deleting files owned by other users. A common example is chmod 1777.

What are setuid and setgid?

setuid runs an executable with the file owner's effective user ID. setgid runs with the file group's ID or causes new files in a directory to inherit its group.

Does this tool change file permissions?

No. It only calculates and generates chmod values and commands. It never accesses or modifies your files.

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