Base Number Converter

Convert numbers between different number systems instantly. Supports binary, octal, decimal, duodecimal, hexadecimal, and base 36 with live conversion and support for large integers.

10
Decimal
2
Binary
16
Hex
Instant multi-base conversion

The Bottom Line

This base number converter instantly transforms numbers between different number systems with live translation as you type. Supports binary (base 2), octal (base 8), decimal (base 10), duodecimal (base 12), hexadecimal (base 16), and base 36. Uses BigInt internally to handle arbitrarily large integers without overflow. Features automatic validation with clear error messages if you type invalid digits for the selected base. Swap bases and chain conversions with a single click. View all supported bases simultaneously for quick reference and copying. Accepts spaces and underscores in input for readability (e.g., 1010_1010 or 1_000_000). Completely privacy-focused—all conversion happens in your browser with no server uploads.

Number Base Converter

Enter a number and select the base to convert from and to:

Base System Guide

Supported Bases

  • Binary (Base 2): Digits 0-1
  • Octal (Base 8): Digits 0-7
  • Decimal (Base 10): Digits 0-9
  • Duodecimal (Base 12): Digits 0-9, A, B
  • Hexadecimal (Base 16): Digits 0-9, A-F
  • Base 36: Digits 0-9, A-Z

Input Tips

  • Spaces and underscores are automatically ignored (e.g., 1010_1010)
  • Negative numbers are supported (e.g., -FF)
  • Integers only; fractional numbers are not supported
  • Input is case-insensitive for letters (a, A, B, b work the same)
  • Large integers are supported using BigInt internally

Problems This Base Number Converter Solves

  • Eliminates manual base conversion - Stop converting between number systems by hand and risking calculation errors. Get instant, accurate conversions between any supported base.
  • Prevents integer overflow - Uses BigInt internally to handle arbitrarily large integers without precision loss, perfect for cryptography and low-level systems work.
  • Removes confusion about allowed digits - Clear error messages tell you exactly which digits are valid for your selected base and which digit you typed wrong.
  • Simplifies hexadecimal work - Convert hex values from memory addresses, color codes, or API responses instantly without external tools.
  • Enables binary debugging - Quickly convert between decimal and binary to understand bitwise operations and debug hardware-level issues.
  • Supports duodecimal calculations - Base 12 is useful in historical and theoretical contexts; this tool makes it accessible.
  • Allows base 36 encoding - Convert numbers to base 36 for compact alphanumeric representation in URLs and identifiers.
  • Chains conversions with swap - The swap button lets you flip the from/to bases and use the output as the new input, enabling quick conversion chains.
  • Shows all bases at once - View the same number in all supported bases simultaneously for instant reference without recalculating.
  • Accepts flexible input format - Input with spaces and underscores for readability (e.g., 1010_1010) and they're automatically stripped during conversion.