Number Base Converter
Type a number and pick its base: binary, octal, decimal, hexadecimal and any base from 2 to 36 update in real time.
How base conversion works
In any positional numeral system, a digit's value depends on its position: in base 10 the number 255 means 2×100 + 5×10 + 5×1, in base 16 the same value is written FF, and in base 2 it becomes 11111111. Beyond 9, letters take over: A is worth 10, B is 11, all the way to Z at 35 — which is why base 36 is the highest base you can write with digits plus the Latin alphabet. This converter uses arbitrary-precision arithmetic (BigInt), so you can paste extremely long numbers without losing a single digit to rounding.
Where binary, octal and hexadecimal show up
Binary is the language of circuits: every bit is a switch that's either on or off.
Hexadecimal is its shorthand (one hex digit = 4 bits) and you'll meet it in CSS colors like
#ff8a5c, in MAC addresses and in memory dumps. Octal lives on in Unix file
permissions: the famous chmod 755 is literally a base-8 number, where each digit
packs the three read-write-execute bits.