← All Tools
Unix Permissions Converter🔒 100% local
Calculate chmod values. Privacy-first, no server uploads, no tracking.
Translates between the two ways chmod is written. Give it octal digits (three or four) or a nine-character symbolic string such as rwxr-xr-x, and it prints the octal form, the symbolic form, a per-triad breakdown with the permission names spelled out, the state of the setuid/setgid/sticky bits, and a ready chmod command line. The whole calculation is string slicing and bit tests inside the page component, so the permissions you paste stay in the tab.
How to use it
- Paste an octal permission like 755 or a symbolic one like rwxr-xr-x into the input box.
- Press Process to fill the Output panel.
- Read the Owner/Group/Others lines for the meaning of each digit, then copy the chmod command at the bottom.
Worked example
755becomesOctal: 0755
Symbolic: rwxr-xr-x
Owner (u): rwx (read, write, execute)
Group (g): r-x (read, execute)
Others (o): r-x (read, execute)
Special bits: (no special bits - 3-digit octal given)
Context: Typical for directories and executables (owner rwx, others rx)
chmod command: chmod 755 <file>shown condensed; the real output keeps the blank separator lines
rwxr-xr-xbecomesOctal: 0755
Symbolic: rwxr-xr-xthe symbolic branch produces the same octal, so this input and 755 give identical output
4755becomesOctal: 4755
Setuid (ON) - run with file owner's privileges
Setgid (off) - run with file group's privileges
Sticky bit (off) - only owner can delete files in directory
chmod command: chmod 4755 <file>a leading fourth digit switches on the special-bit report
When to use it
- A deploy script or Dockerfile lists chmod 640 and you want to see at a glance who can do what.
- You are writing SSH or key-file permissions and need to confirm that 600 on a private key means owner-only.
- You inherited a directory with an odd mode such as 2775 or 1777 and want the setgid or sticky bit explained.
What it does not do
- The symbolic branch only fires on exactly nine characters from the set rwx-. Relative forms like u+x, go-w or a=r are not understood, and symbolic setuid such as rwsr-xr-x is rejected, because the leading s or t breaks the nine-character pattern.
- The human-readable Context line exists for only five digests - 644, 755, 600, 777 and 700. Any other mode still converts correctly but leaves that line empty.
- Nothing is changed on any machine: the tool only prints a chmod command for you to run yourself.
- Four-digit input is read as special-bits plus three digits, so 0755 is treated as having a special-bits block (all off) rather than as a plain 755.