Online chmod calculator: toggle the rwx permission matrix to get the octal (755), symbolic (rwxr-xr-x) form and the chmod command instantly; or type 755 / rwxr-xr-x to reverse-lookup. Includes setuid/setgid/sticky bits and common permission presets.
TL;DR: chmod calculator: toggle the rwx matrix for instant octal and symbolic output, with reverse lookup, special bits and common presets.
This tool runs entirely in your browser. Open DevTools → Network panel and search your input — it appears in no request.
FAQ
7 = owner can read, write, execute; 5 = group and others can read and execute. Each digit is the octal sum of rwx: r=4, w=2, x=1. 755 is the norm for executables and directories.
Nine characters in three groups: first three for owner, middle for group, last for others. r = read, w = write, x = execute, - = none. rwxr-xr-x equals 755.
setuid (4xxx) runs an executable as its file owner, like /usr/bin/passwd; setgid (2xxx) on a directory makes new files inherit the directory group; sticky (1xxx) allows only the file owner to delete it, like /tmp. Enabling them turns the octal into four digits.
600 means only the owner can read and write. OpenSSH rejects private keys with wider permissions ("Permissions 0777 too open"). Toggle 600 here and copy the command.
Related Tools
Related Articles
Docker permission denied on docker.sock: the Right Fix (and Its Security Cost)
docker commands fail with permission denied while trying to connect to the Docker daemon socket? The cause: your user isn't in the docker group. One-step fix with usermod -aG, the newgrp trick to avoid re-login, why chmod 777 is a trap, and why docker group membership equals passwordless root — plus the rootless alternative.
Online CIDR Calculator: Subnet Division and IP Address Planning
Learn CIDR (Classless Inter-Domain Routing) fundamentals. Understand subnet masks, network/broadcast addresses, and how to use an online calculator for IP address planning.