chmod Rechner

Convert Octal and Symbolic Permissions

The chmod Calculator helps you visualize and convert Linux file permissions between octal and symbolic notations. You can enter a numeric value like 755 or 4755 to see the corresponding symbolic representation, while also accounting for special bits such as SUID, SGID, and Sticky bits. This visual approach ensures that you understand exactly what rights are being granted to the owner, group, and others before applying them in your terminal.

Practical Presets for System Administration

Manage permissions safely using pre-defined configurations tailored for common scenarios. The tool includes specific presets for web files, configuration scripts, and system directories like /tmp. It helps you distinguish between standard executable permissions and special bits used for shared folders or setuid programs. By using these shortcuts, you can quickly determine the correct chmod values for SSH keys, script executions, and multi-user environment settings without making manual calculation errors.

Secure and Private Processing

Your data privacy is a priority when managing system permissions. The chmod Calculator processes all calculations directly in your web browser. No file information, system paths, or permission strings are ever sent to an external server. This ensures that even when you are calculating permissions for sensitive configuration files or private keys, your data remains local and secure. It is a purely client-side tool designed to simplify your workflow without compromising security.

What is the difference between octal and symbolic chmod?

Octal notation uses numbers like 755 to represent permissions, while symbolic notation uses letters like u+rwx. Our calculator allows you to toggle between these formats instantly so you can choose the method that best fits your current workflow or script requirements.

What do special bits like SUID and SGID do?

SUID allows a program to run with the privileges of the file owner, while SGID is useful for shared directories where new files inherit the group ID. The tool helps you visualize these complex configurations clearly before you apply them.

How do I set correct permissions for web server files?

For typical web files and configuration scripts, you need specific combinations of read, write, and execute bits. Use the Typical for Web preset in our calculator to quickly find the correct octal value that balances functionality with security requirements.

What is the Sticky Bit used for?

The Sticky Bit is commonly used on public directories like /tmp. It ensures that only the owner of a file or directory can delete or rename it, even if other users have write access to the parent folder. Our calculator helps you identify this bit.