What does chmod 600 mean?

600 (rw-------) lets the owner read and write the file and gives the group and everyone else no access. It is the usual mode for SSH private keys: OpenSSH refuses to use a key file that other users can read.

How do I make a file executable in Linux?

Run chmod +x filename to add the execute bit for all users, or chmod 755 filename to set full owner permissions plus read/execute for others.

What does ls -l show about file permissions?

The first column of ls -l output shows permissions in symbolic form, e.g. -rwxr-xr-x. The first character is the file type (- for file, d for directory, l for symlink). The next nine characters are three rwx groups for owner, group, and other.

What does chmod 777 do?

chmod 777 gives read, write and execute to the owner, the group and every other account (rwxrwxrwx), so any user on the machine can change or replace the file. Web servers rarely need it: 644 for files and 755 for directories covers most setups.

Linux file permissions

Build or decode Linux file permissions with a simple click interface. Set read, write, and execute permissions for owner, group, and other, and instantly see the numeric chmod value and symbolic representation.

How it works

The tool converts between octal, symbolic, and binary permission representations using pure JavaScript bit arithmetic. No library required. Checking a box sets the corresponding bit; typing an octal value like 755 reverses the process to tick the right boxes.

Processing runs in your browser

All calculations happen locally in the page. Our servers are not involved at any point.

Related operations

For subnet math like host counts and netmasks, try the CIDR calculator. To convert numeric permission bits between bases, use the number base converter. For testing permission patterns in path strings, see the regex tester.

Frequently asked questions

What does chmod 600 mean?: 600 (rw-------) lets the owner read and write the file and gives the group and everyone else no access. It is the usual mode for SSH private keys: OpenSSH refuses to use a key file that other users can read.
How do I make a file executable in Linux?: Run chmod +x filename to add the execute bit for all users, or chmod 755 filename to set full owner permissions plus read/execute for others.
What does ls -l show about file permissions?: The first column of ls -l output shows permissions in symbolic form, e.g. -rwxr-xr-x. The first character is the file type (- for file, d for directory, l for symlink). The next nine characters are three rwx groups for owner, group, and other.
What does chmod 777 do?: chmod 777 gives read, write and execute to the owner, the group and every other account (rwxrwxrwx), so any user on the machine can change or replace the file. Web servers rarely need it: 644 for files and 755 for directories covers most setups.

Last reviewed September 30, 2026

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	Read	Write	Execute	Value
Owner				7 (rwx)
Group				5 (r-x)
Other				5 (r-x)