HEX to Octal

HEX to Octal Converter — Convert Hexadecimal to Octal Online

The HEX to Octal Converter is a free online tool that translates hexadecimal (base-16) numbers into their octal (base-8) equivalents. While octal is less common in modern computing than hex or binary, it remains essential for Unix file permissions, certain assembly languages, legacy systems, and specific cryptographic implementations — making this conversion useful for sysadmins, security researchers, and students of computer science.

HEX vs Octal — When You Need Each

Hexadecimal uses 16 digits (0-9, A-F) where each digit represents 4 binary bits. Octal uses 8 digits (0-7) where each digit represents 3 binary bits. Hex is the standard for memory addresses, color codes, and binary data dumps because of its tight 4-bit mapping. Octal is the standard for Unix file permissions (chmod 755), older PDP-11 assembly, certain Cisco IOS commands, and some legacy protocols. Converting between them requires going through binary as an intermediate step — the tool handles this calculation automatically.

How to Use the Converter

Paste your hexadecimal value into the input box (with or without the 0x prefix, with uppercase or lowercase letters). Click Convert and the octal equivalent appears instantly. The tool handles values of any length, from single bytes to long cryptographic keys, with no rounding errors.

Common Use Cases

System administrators convert hex permission masks to Unix octal. Embedded developers translate between vendor documentation formats. Cryptography students explore base conversions. Reverse engineers work with legacy binary file structures. The tool is free, instant, mobile-friendly, runs entirely in your browser, and requires no signup. Bookmark it for fast base conversions whenever you need them.

Tamer Baghdadi

CEO / Co-Founder