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.
For local tools, open DevTools → Network and search your input — it should not appear in requests.
Usage Guide
chmod calculator — local browser tool; verify options on screen.
1. Use
Follow on-screen options; copy results locally.
- Open the tool.
- Set options.
- Copy output.
2. Scope
Capabilities match the visible UI, not wishful docs.
3. Checks
- Tiny sample first.
- Note options used.
- Keep PII private.
4. Limits
Browser memory and format edge cases still apply.
5. Related
Pair with sibling converters/checkers on this site.
6. Handoff
Document source, options, and known boundaries when sharing.
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.
On a directory, x means the right to enter and traverse it. Keep r but drop x and you can list filenames yet cannot access anything inside. Directories and executables commonly use 755 and regular files 644 — run ls -l first to see the current mode before changing it.
Recursion touches everything under the path and can widen permissions on files that should stay tight, such as 600 private keys. Pin down the exact path first, or scope the change with find so it hits only directories or only files. If access still fails afterwards, check ACLs and mount options — extended permissions are not visible in the octal mode.
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