Orthogonal

Free Number Base Converter Online — Binary, Hex, Octal, Decimal

By Orthogonal Editorial TeamPublished Updated 2 min read

Affiliate disclosure: This post contains affiliate links. If you buy through them I earn a commission at no extra cost to you. As an Amazon Associate I earn from qualifying purchases.

Convert numbers between binary, octal, decimal, and hexadecimal instantly with this free online base converter. Type a value in any field and the others update in real time — essential for programmers, students, and anyone working with low-level data. Runs entirely in your browser.

On this page
  1. How to Use This Base Converter
  2. Understanding Number Bases
  3. Common Conversions
  4. Where You’ll Use Each Base
  5. Privacy
  6. Recommended Reading
  7. More Free Developer Tools

How to Use This Base Converter#

  1. Type a number into any of the four fields
  2. The other bases update instantly
  3. Invalid input for a base is flagged automatically





Understanding Number Bases#

A number base (or radix) defines how many unique digits represent values. Computers use binary internally; programmers often use hex and octal as compact shorthand.

  • Decimal (base 10) — digits 0–9, the everyday number system
  • Binary (base 2) — digits 0–1, how computers store all data
  • Hexadecimal (base 16) — digits 0–9 and A–F, used for colors, memory addresses, and byte values
  • Octal (base 8) — digits 0–7, used in Unix file permissions

Common Conversions#

  • 255 decimal = 11111111 binary = FF hex = 377 octal
  • 16 decimal = 10000 binary = 10 hex = 20 octal
  • 8 decimal = 1000 binary = 8 hex = 10 octal

Where You’ll Use Each Base#

  • Hex — CSS colors (#FF5733), memory addresses, MAC addresses, byte dumps
  • Binary — bitwise operations, flags, low-level hardware programming
  • Octal — Unix/Linux file permissions (chmod 755)

Privacy#

All conversions run in your browser using JavaScript’s built-in number parsing. Nothing is sent to any server.

Go deeper into how computers represent and process numbers:

More Free Developer Tools#

Like these free tools? We build more every week. Follow our AI Tools Telegram channel for weekly picks of the best developer tools, or check out our Market Intelligence channel for AI-powered trading insights.

Share