Unix CHMOD Calculator

Calculate octal and symbolic file permissions visually.

Drop a file or click to open
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Owner
Group
Others
Octal Notation 000
Symbolic Notation ---------
Shell Script

Common Presets

Standard Web Folder (755)

Recommended for public directories: Owner can do everything, others can only read and execute.

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Standard Web File (644)

Recommended for public files: Owner can read/write, others can only read.

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Private Secure File (600)

Highly secure: Only the owner can read and write the file.

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Full Permissions (777)

Danger! Everyone has full control. Use only for temporary troubleshooting.

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Understanding CHMOD

CHMOD (Change Mode) is a fundamental command in Unix-like operating systems that defines who can read, write, or execute a file or directory.

Permissions are divided into three tiers: Owner (the user who created the file), Group (a collection of users), and Others (everyone else).

Octal vs Symbolic

  • Octal (Numeric): Uses three digits (0-7) to represent permissions (e.g., 755).
  • Symbolic: Uses a 10-character string like -rwxr-xr-x.
  • Calculations: Read = 4, Write = 2, Execute = 1. Add them up for each tier.