What chmod 755 does: owner can write, everyone can read and run
Runs in your browser. Nothing you type is sent anywhere. Updated on 24 Oct 2026.Chmod 755 is the usual mode for programs, scripts and web directories. The owner digit 7 means read, write and execute; the two 5s give the group and everyone else read and execute only, so they can run the script or list the directory but not change it. In ls -l it shows as rwxr-xr-x. Change any box to see how the number and the command change.
Open the page with 755 already set: rwxr-xr-x.
Read the breakdown: the owner can read, write and execute; group and others can read and execute.
Type the script or directory name in File or directory, and turn on -R (recursive) for a folder tree.
Press Copy for the chmod 755 command.
This chmod calculator converts Unix and Linux file permissions between the octal number, such as 755, and the symbolic letters that ls -l prints, such as rwxr-xr-x. Tick the read, write and execute boxes for the owner, the group and everyone else, type a number, or paste the permission column from ls -l, including the leading file type letter; all three stay in step.
Each digit is a sum: read is 4, write is 2 and execute is 1. The owner's 7 is 4 + 2 + 1, the group's 5 is 4 + 1. A fourth digit in front holds the special bits: setuid (4) runs a program as its owner, setgid (2) runs it as its group or makes a directory's new files inherit the group, and sticky (1) lets people delete only their own files in a shared directory like /tmp. In the letters these show as s or t in the execute position, and as a capital S or T when execute is not also set, which usually means a mistake.
The command line underneath is ready to copy, in numeric form (chmod 755 file) or symbolic form (chmod u=rwx,g=rx,o=rx file), with -R for a whole directory tree and your file name quoted for the shell if it contains spaces. Warnings appear for modes that are usually a mistake, such as a world-writable file.
The rest of the article, and all 6 questions about Chmod Calculator, are on the Chmod Calculator page.
The owner gets 7, which is read (4) plus write (2) plus execute (1). The group and everyone else get 5, read plus execute. So anyone can run the program or open the directory, but only the owner can change it. In ls -l it appears as rwxr-xr-x.
Both let only the owner write. 755 adds execute for everyone, which a script, a program or a directory needs; 644 leaves execute off, which suits ordinary files such as web pages, images and configuration. Giving a plain file 755 is harmless but unnecessary.
Mode 777 lets every user on the machine change, replace or delete the file, and run it. On a web server that means any compromised process can rewrite your code. Directories that really must be shared should use 1777, which adds the sticky bit so people can delete only their own files.
Programs normally create files with 666 and directories with 777, and every bit set in the umask is removed. With umask 022, files come out as 644 and directories as 755. With 077 they are 600 and 700, private to the owner. A umask never adds permissions.
Still stuck? Ask about Chmod Calculator and anybody who knows can answer. No account needed.
On the related tools: TSV to JSON – Convert tab-separated values, such as a paste from Excel, into JSON · Query String Parser – Split a URL query string into a table of decoded parameters.