chmod Calculator

chmod (change mode) is a Unix command that changes file and directory permissions. Permissions control who can read, write, or execute a file.

755 means: Owner can read, write, execute (7=rwx). Group can read and execute (5=r-x). Others can read and execute (5=r-x). This is typical for web server directories.

644 means: Owner can read and write (6=rw-). Group can only read (4=r--). Others can only read (4=r--). This is standard for web files.

Symbolic notation uses letters: r=read, w=write, x=execute, with - for no permission. Example: rwxr-xr-x = 755.

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