Hey PH! 👋 This started as a personal itch: every time I set up an EC2 instance, SSH would yell "WARNING: UNPROTECTED PRIVATE KEY FILE" at me, and every time I'd end up on some 2012 forum thread trying to remember whether the fix was 400 or 600. So I built chmodtool. It's deliberately boring, in a good way: a calculator that converts between octal (755), checkboxes, and symbolic notation (-rwxr-xr-x) in real time, plus step-by-step fix pages for the SSH/AWS .pem permission errors — including the Windows icacls commands nobody ever writes down. A few things I learned along the way: 777 is the duct tape of Unix (it "works" until it really doesn't), and half of all permission problems are just people copy-pasting commands they don't trust. That's why every result comes with a plain-English explanation, not just a number. No signup, no paywall, works on mobile. Tell me which permission headache I should cover next — chown? umask? I'm listening.

chmodtool.com

Stop googling what chmod 755 means

Stop googling what chmod 755 means