What are number bases?

A number base defines how many digits a numbering system uses. Decimal (base-10) uses 0–9. Binary (base-2) uses 0–1. Hexadecimal (base-16) uses 0–9 and A–F. Octal (base-8) uses 0–7.

Why do programmers use hexadecimal?

Hex is compact and maps cleanly to binary — each hex digit represents exactly 4 bits. It's used for memory addresses, color values (like #FF5733), and binary data display.

Is there a limit to the number size?

This tool uses JavaScript's built-in number parsing, which handles integers up to 2^53 safely. For very large numbers you'd need a big integer library.

How do I read binary?

Each digit is a power of 2. Reading right to left: 1, 2, 4, 8, 16... So binary 1011 = 8+2+1 = 11 in decimal.

Number Base Converter

Convert numbers between decimal, binary, hexadecimal and octal bases instantly.

Enter a number in any field — all others update instantly.

Decimal

Binary

Hexadecimal

Octal

All representations

Decimal—

Binary0b—

Hexadecimal0x—

Octal0o—

Frequently asked questions

Number Base Converter — Binary, Hex, Decimal, Octal

Convert numbers between decimal, binary, hexadecimal, and octal bases instantly. Essential for programmers, students, and anyone working with low-level computing, color values, or bitwise operations.

All 4 bases at once

Enter a number in any base and see the equivalent in decimal, binary, hex, and octal simultaneously.

Instant conversion

Results update as you type — no submit button needed.

Browser-only

Runs entirely in your browser with no server involved.

Whether you're studying computer science, debugging memory addresses, or working with color codes — base conversion is a fundamental programming tool.