About chmodtool

What chmodtool does

chmodtool is a free permission calculator and troubleshooting reference. It converts Unix permissions between octal values, symbolic notation, and checkbox selections, then explains when common modes such as 755, 644, 600, and 400 are appropriate.

Why it exists

Permission numbers are easy to forget, and errors such as "permissions too open" can interrupt work with SSH and AWS private keys. This site brings the conversion, practical explanation, and common fixes together so you can find an answer and get back to the task at hand.

How to use it

No registration or login is required, and the site is free to use. Start with the chmod calculator or open the guide for the permission or error you are working with.

Contact

For general questions, email support@chmodtool.com. For privacy questions, email privacy@chmodtool.com. You can also read the Privacy Policy and Terms of Service.

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