chmod 624 Permission Explained
Summary: chmod 624 gives the owner read/write, the group write, and everyone else read.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 6 | |||
| Group (g) | 2 | |||
| Others (o) | 4 |
chmod 624 filename
chmod 624 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 6 |
rw- |
Read and write | Can list names, cannot enter |
| Group (g) | 2 |
-w- |
Write only (rarely useful) | No practical effect without x |
| Others (o) | 4 |
r-- |
Read only | Can list names, but not enter |
Is chmod 624 Safe?
Moderate
- Every member of the group can modify this file.
- Any user can read this file — never use it for secrets such as keys or .env files.
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
624 is uncommon in standard Linux setups. The closest widely used permission is chmod 664.
chmod 624 Command Examples
# Apply using octal mode
chmod 624 filename
# Apply using equivalent symbolic mode
chmod u=rw,g=w,o=r filename
# Recursive command warning:
chmod -R 624 /path/to/dir
# Note: -R applies the same mode to files and directories. Use find to treat them separately:
find /path/to/dir -type f -exec chmod 624 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-rw--w-r-- 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 153 makes new directories 624 and new files 624. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 624 mean?
chmod 624 gives the owner read/write, the group write, and everyone else read. In octal notation, the owner receives 6 (read/write), the group receives 2 (write), and others receive 4 (read).
Is chmod 624 safe?
chmod 624 is classified as Moderate. Every member of the group can modify this file.
What is chmod 624 in symbolic notation?
In symbolic notation, chmod 624 is represented as rw--w-r--. You can apply this permission using the equivalent symbolic command "chmod u=rw,g=w,o=r filename".
Related Permissions
Change one bit: