Chmod Calculator
Calculate Unix file permissions with visual checkbox interface. Free online chmod calculator for numeric and symbolic modes.
| Permission | Owner | Group | Others |
|---|---|---|---|
| read | |||
| write | |||
| execute |
Numeric: 644 Symbolic: -rw-r--r-- chmod 644 file.txt
What is Chmod Calculator?
chmod (change mode) is a Unix command that sets file permissions for the owner, group, and others. Permissions control who can read (r), write (w), and execute (x) a file. The numeric format uses three octal digits (e.g., 755), while the symbolic format uses letters (e.g., rwxr-xr-x). Understanding chmod is essential for server administration and deployment.
How to Use
- Check or uncheck the Read, Write, and Execute boxes for Owner, Group, and Others
- The numeric (755) and symbolic (rwxr-xr-x) values update instantly
- Or enter a numeric value directly to see the checkboxes update
- Copy the chmod command to use in your terminal
Examples
Common web file permission
Private file
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Frequently Asked Questions
What does each digit in chmod 755 mean?
The first digit (7=rwx) is the owner's permissions. The second digit (5=r-x) is the group's permissions. The third digit (5=r-x) is others' permissions. 7=4+2+1 (read+write+execute), 5=4+1 (read+execute).
What is the difference between chmod and chown?
chmod changes file permissions (who can read/write/execute). chown changes file ownership (who the file belongs to). Use chown to change the owner, then chmod to set what they can do.
What is the most common chmod value for web servers?
755 for directories and executable scripts (owner can do everything, others can read and execute). 644 for regular files (owner can read/write, others can only read). Never use 777 in production as it allows everyone to write to the file.