Unix chmod Helper — Permissions, Free
Translate owner, group and other read/write/execute selections into octal and symbolic permissions. The calculator explains mode bits without changing any server file permissions.
- Runs in your browser
- Nothing is uploaded
- No signup; device limits apply
Numbers stay on your device. Nothing is sent to a server.
How to use this tool
Select r, w and x for each user category. Remember that directory execute permission allows traversal, and check the intended target and purpose before applying a resulting mode.
Results and examples
Owner rwx with group and other r-x gives 755 and rwxr-xr-x. A displayed chmod number is not a complete operation; an actual command also needs a target path.
Limitations
- ACLs, umask, setuid, setgid and sticky bits are not modelled.
- A permissive mode such as 777 is not a universally safe fix.
Fields
| Field | Guidance and constraints |
|---|---|
| Owner read | Check the unit and format displayed beside this field. |
| Owner write | Check the unit and format displayed beside this field. |
| Owner execute | Check the unit and format displayed beside this field. |
| Group read | Check the unit and format displayed beside this field. |
| Group write | Check the unit and format displayed beside this field. |
| Group execute | Check the unit and format displayed beside this field. |
| Others read | Check the unit and format displayed beside this field. |
| Others write | Check the unit and format displayed beside this field. |
| Others execute | Check the unit and format displayed beside this field. |
Data handling
Processing stays in the current browser tab; the site does not upload tool input for the calculation itself.
Sources
Frequently asked questions
What permissions does 755 mean?
Owner rwx with group and other r-x gives 755 and rwxr-xr-x. A displayed chmod number is not a complete operation; an actual command also needs a target path.
Does the tool change server permissions?
ACLs, umask, setuid, setgid and sticky bits are not modelled. A permissive mode such as 777 is not a universally safe fix.
Related tools
You do not need to start over. Continue with the tool that fits your next step.
