Decimal to Binary Converter

Decimal is the base-10 system humans use, with digits 0 through 9. Binary is base-2, using only 0 and 1, which is how data is physically represented in a computer's memory and registers. Converting from decimal to binary means rewriting the same quantity as a sum of powers of two: for example, 13 becomes 1101, because 8 + 4 + 0 + 1 = 13. Hexadecimal (base-16) and octal (base-8) are shorthand for binary because each hex digit maps to exactly four bits and each octal digit to three, making long bit strings easier to read. This tool does the conversion with the browser's built-in Number.toString method after parsing your input with parseInt in base 10. That means it works on standard JavaScript numbers, so reliable, exact results are limited to safe integers up to 9,007,199,254,740,991 (2^53 - 1). Negative numbers are shown in sign-magnitude form with a leading minus, not in two's-complement, and any fractional part you type is truncated before conversion. There is no fixed bit width or zero padding: you get the minimal representation of the value.