How to Convert Between Number Bases Online (Binary, Octal, Decimal, Hex)

Working with different number bases is common in programming and computer science. Binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) each have their uses. This guide shows you how to convert between number bases online using fixie.tools — a free calculator that handles all common bases instantly.

Step 1: Open the Number Base Converter

Navigate to fixie.tools/base-convert. No signup needed.

Step 2: Enter Your Number

Type the number you want to convert. Select the input base (binary, octal, decimal, hex, or any custom base from 2 to 36).

Step 3: View Conversions

The tool instantly displays your number in all common bases simultaneously: binary, octal, decimal, and hexadecimal. Custom base conversions are also available.

Step 4: Copy Results

Copy any converted value with one click. The tool formats binary with grouping (e.g., 1010 0011) and hex with 0x prefix for easy use in code.

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Frequently Asked Questions

Is the base converter free?

Yes, completely free with no signup required.

What bases are supported?

Binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), and any custom base from 2 to 36.

Why do programmers use hexadecimal?

Hexadecimal provides a compact way to represent binary data — each hex digit maps to exactly 4 binary bits. Colors in CSS use hex (e.g., #FF6B6B), and memory addresses are typically shown in hex.

Can I convert large numbers?

Yes, the tool handles very large numbers using JavaScript's BigInt capabilities, allowing conversion of numbers beyond standard integer limits.

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