Chmod Calculator
Pick read/write/execute bits and get the octal mode plus the chmod command
| Identity | Read r (4) | Write w (2) | Execute x (1) | Value |
|---|
Instructions
chmod Permission Calculator Instructions\n\n## Overview\nLinux file permissions come in two forms: octal (755) and symbolic (rwxr-xr-x). This tool lets you convert between them by checking boxes, so you avoid mistakes that leave files unopenable or permissions too wide open.\n\n## How to Use\n1. In the table, check the read (r=4), write (w=2) and execute (x=1) permissions for owner, group and others\n2. The value for each group appears on the right in real time, and the three-digit octal, four-digit octal and symbolic forms are shown below\n3. You can also type 755 directly into the "octal" input box and the checkboxes will sync in reverse\n4. Click a common permission button to quickly apply 644 / 600 / 755 / 700 / 775 / 777\n5. The dark box at the bottom holds a copy-ready `chmod xxx filename` command\n\n## Notes\n- 777 means anyone can rewrite the file, so do not use it in production; the usual practice for website directories is 644 for files and 755 for directories\n- Give execute permission (x) only to scripts that actually need to run; plain text files and images do not need x\n- Each octal digit can only be 0-7; if you enter 8 or 9 the tool takes the value per digit and shows a hint\n- For directories, x means "you can enter this directory", which differs from the meaning of x on files
❓ FAQ
Where are 644 and 755 used?
644 is for regular files: the owner can read and write, others can only read. 755 is for directories and scripts that need to run: the owner can read, write and execute, others can read and execute.
Why can't 777 be used in production?
777 means anyone can modify the file. If a website directory is 777, an attacker only needs to find an upload entry point to replace it with their own script and run it, which is very risky.
What does x mean in directory permissions?
For a directory, x means "you can enter it and look up files inside it". If a directory has no x, you cannot access the files inside even if it has r permission.
🔗 Related Tools
📝 Related Articles
How to Use a Favicon Generator: Complete Steps from Image to Website Icon
Use a favicon generator to turn a square image into a website icon that displays correctly in browser tabs and on mobile home screens. From preparing assets to deployment troubleshooting, this covers it all in one go—just follow along to get it done.
tool-tutorialsHow to Use a Cron Expression Generator: Complete Beginner Steps
Use an online tool to select the five time fields, automatically generate a standard Cron expression with a human-readable time explanation, and learn to troubleshoot execution time deviations caused by time zones and field counts, so complex schedules no longer rely on guesswork.
tool-tutorialsHow to Use an Online CSV to JSON Tool: Beginners Can Get Started in Three Steps
Use a three-step process to complete an online CSV to JSON tool operation, covering option settings, result validation, error troubleshooting, large file handling, mobile operation, and API debugging scenarios. Beginners can follow along to get usable JSON data.
tool-tutorialsWhat Is HTML Formatting? A Beginner's Guide to the Key Points
Use a browser-based HTML formatting tool that runs locally to restore compressed or messy HTML into an indented, readable structure. Also understand the difference between formatting and minification, the troubleshooting order for messed-up indentation, and how to handle large files getting stuck and mobile no-install solutions.