Unix Permission Converter

Convert between symbolic (rwxr-xr-x) and octal (755) permission notation — with a full per-audience breakdown.

Tool input is processed locally in your browser and is not submitted to CodeNimbleTools. Avoid pasting production secrets into any device or website you do not fully trust.

Permission — symbolic (rwxr-xr-x) or octal (755, 0644, 2775)

Conversion

Type either form above — it converts both ways automatically with a full breakdown.

About this tool

ls -l shows rwxr-xr-x; chmod wants 755. This converter translates both directions automatically — type either form and get the other, plus a table explaining exactly what owner, group and others may do.

Special-bit letters (s, S, t, T) are fully supported, so 4-digit octals like 2775 round-trip correctly.

How to use it

Type a symbolic string (with or without the leading file-type character) or an octal number.
The converter detects the format and translates instantly.
Read the per-audience breakdown table.
Copy the equivalent chmod command.

Useful ways to apply it

Decoding ls -l output into a chmod-able number.
Verifying what 2755 or 4755 actually mean before applying them.
Teaching the relationship between the two notations.
Auditing permissions listed in deployment docs.

Worked example

Example input

rwxr-xr-x

Expected output

Edge cases to check

Special permission characters s/S/t/T require extra interpretation.
ACLs can grant access not visible in the basic mode string.

Known limitations

Traditional mode bits are only part of a Unix permission decision; ownership and ACLs still matter.

How this tool was reviewed

Reviewed with symbolic and octal modes plus special-bit warnings.

Last reviewed: September 3, 2026 · Maintainer: William

Standards and technical references

Linux inode permissions

See the site-wide testing methodology for fixture categories, privacy checks and correction policy.

Frequently asked questions

What's the difference between s and S?

Lowercase s means the special bit AND execute are both set; uppercase S means the special bit is set but execute is not — usually a misconfiguration worth checking.

Can I paste ls -l output directly?

Paste the 10-character permission block (like -rwxr-xr-x or drwxr-xr-x) — the leading type character is accepted and ignored.

Why does my 4-digit octal show letters in the symbolic form?

The first digit encodes setuid/setgid/sticky, which appear as s/S in owner/group execute positions and t/T in the others position.

Privacy

Tool input is processed locally in your browser and is not submitted to CodeNimbleTools. Avoid pasting production secrets into any device or website you do not fully trust.