chmod calculator
Toggle permission bits for owner, group, and others. Get the octal value, symbolic notation, and plain-English description. Runs entirely in your browser — nothing sent to a server.
| read (4) | write (2) | execute (1) | value | |
|---|---|---|---|---|
| Owner | 7 | |||
| Group | 5 | |||
| Others | 5 |
bit reference ▼
chmod reference
What does chmod 755 mean?
Owner: read + write + execute (7). Group: read + execute (5). Others: read + execute (5). Symbolic: rwxr-xr-x. Standard for web server directories and scripts — others can read and run, only owner can modify.
What does chmod 644 mean?
Owner: read + write (6). Group: read only (4). Others: read only (4). Symbolic: rw-r--r--. Standard for regular files, HTML/CSS/JS served by nginx or Apache. Anyone can read; only owner can change.
Why is chmod 777 dangerous?
777 gives read, write, and execute permission to everyone on the system. On a web server or shared host, any process can overwrite or execute the file. Use 755 for directories, 644 for files.
How do I apply chmod recursively?
Use chmod -R 755 /path to apply permissions recursively. For mixed file/directory permissions use: find /path -type f -exec chmod 644 {} \; plus find /path -type d -exec chmod 755 {} \;