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Chmod Calculator

Convert between octal (755) and symbolic (rwxr-xr-x) Unix file permissions. Interactive checkbox matrix with common presets. Runs entirely in your browser — your data never leaves your machine.

chmod permissions unix linux file-system octal developer-tools

Published May 28, 2026

All interactive tools run entirely in your browser. Your data never leaves your device.

How It Works

Enter an octal value (e.g. 755) or symbolic string (e.g. rwxr-xr-x) and the tool converts bidirectionally. Use the checkbox matrix for visual editing, or click a preset for common configurations.

Features

  • Bidirectional conversion: octal to symbolic and symbolic to octal
  • Interactive matrix: checkbox grid for owner/group/others x read/write/execute
  • Command preview: ready-to-use chmod command with copy button
  • Common presets: 755, 644, 777, 700, 600, 444, 666, 750
  • Human-readable description: explains what each role can do
  • Private: runs entirely in the browser — no data transmitted

Permission Reference

DigitSymbolicMeaning
0---No permissions
1--xExecute only
2-w-Write only
3-wxWrite + execute
4r--Read only
5r-xRead + execute
6rw-Read + write
7rwxRead + write + execute

Use Cases

  • Setting correct permissions on deployment scripts and config files
  • Translating symbolic notation from ls -la output to octal for chmod
  • Teaching Unix file permissions with the visual checkbox matrix
  • Quick reference for common permission patterns (644, 755, etc.)