DevConvertor

Binary Converter

Convert a value between binary, octal, decimal, and hexadecimal — edit any one and the others update to match. Uses BigInt throughout, so large integers convert exactly instead of losing precision through floating-point math.

Edit any field — the others update to match

ReadyDeveloper UtilitiesFree · No account required

Related tools

Roman Numeral ConverterConvert between numbers and Roman numerals, in both directions.Base64 EncoderEncode text to Base64, with full Unicode support.Octal ConverterConvert between octal, binary, decimal, and hexadecimal.

Features

  • Binary, octal, decimal, and hexadecimal, synchronized — edit any one
  • Exact precision for large integers via BigInt, never floating-point rounding
  • Negative values supported in every base
  • Clear, specific error for an invalid digit in the selected base

How to use

  1. Type a value into any of the four fields.
  2. The other three update automatically to match.

Example

255 decimal = 11111111 binary = FF hex = 377 octal

FAQ

Does this lose precision on very large numbers?
No. It uses JavaScript's BigInt type throughout instead of the regular Number type, which only represents integers exactly up to 2^53. A value like 9007199254740993 (2^53 + 1) converts and round-trips exactly here — a Number-based converter would silently round it.
Are negative numbers supported?
Yes, with a leading minus sign, in any of the four bases — the sign is preserved through the conversion.
What counts as an invalid digit?
Each base only accepts its own digits: binary accepts 0-1, octal 0-7, decimal 0-9, and hex 0-9 plus A-F (case-insensitive). Entering a digit outside that range — like a 2 in a binary field — shows exactly which character is invalid.