chmod Calculator: Permissions to Octal and Back (755, 644, 600)
Tick read, write and execute for owner, group and others to get the chmod number, symbolic form and command. Or type 755 and see what it means.
Tick the permission boxes, or type an octal mode like 755. The calculator shows the matching symbolic form, the ls -l style string and the chmod command, and warns about risky modes.
| Read (4) | Write (2) | Execute (1) | |
|---|---|---|---|
| Owner | |||
| Group | |||
| Others |
Common modes
| Mode | Symbolic | Typical use |
|---|---|---|
| 644 | rw-r--r-- | Normal files |
| 755 | rwxr-xr-x | Scripts and folders |
| 600 | rw------- | Private keys and secrets |
| 700 | rwx------ | Private folders such as ~/.ssh |
| 664 | rw-rw-r-- | Files shared with a group |
| 750 | rwxr-x--- | Folders for a group only |
| 777 | rwxrwxrwx | Avoid: anyone can change it |
Frequently asked questions
- What does chmod 755 mean?
- The owner can read, write and execute. The group and everyone else can read and execute.
- Which permissions do SSH keys need?
- Private keys should be 600 and the ~/.ssh folder 700. SSH refuses keys that other users can read.
- Is chmod 777 safe?
- No. It lets every user change the file. Use a narrower mode and fix ownership with chown instead.
- What are setuid, setgid and sticky?
- Special bits. Setuid and setgid run a program as its owner or group. Sticky on a folder, like /tmp, stops users deleting each other’s files.
More tools
Code formatters
CSS beautifier CSS minifier HTML beautifier HTML minifier JavaScript beautifier JavaScript minifier JSON formatter YAML formatter XML formatter SQL formatter Markdown preview
Converters
Base64 encoder and decoder URL encoder and decoder Unix timestamp converter CSV to JSON JSON to CSV HTML entity encoder and decoder Number base converter Time zone converter JSON to TypeScript XML to JSON HTML to Markdown Date difference calculator
Text tools
Regex tester Remove duplicate lines Lorem ipsum generator Word counter Case converter Text diff checker
Color and images
Color converter Contrast checker Image to Base64 Image resizer
Network
Subnet calculator Download time calculator Common ports list CIDR to IP range IPv6 address expander and compressor MAC address formatter curl command builder
Server and files
Cron expression explainer HTTP status codes
Encoding and security
Password generator UUID generator Hash generator JWT decoder QR code generator Password strength checker Wi-Fi QR code generator