Binary ↔ Hexadecimal Converter

You are staring at a memory dump, a register mask or a colour value and you need to get from 11010110 to D6 without doing it in your head or digging out the system calculator. The two fields here mirror each other: type on either side and the other updates on every keystroke, in both directions. Below them, the same binary is shown grouped four bits at a time.

The conversion is direct because each group of 4 bits, a nibble, maps to exactly one hex digit. Nothing is routed through decimal, so a 64, 128 or 256-bit string comes out right, while converters that parse to an integer break past 2 to the 53rd. When the binary does not fill a multiple of four, it is padded with leading zeros: 101 becomes 0101, which is 5.

An invalid character is not erased from the field, it is simply ignored in the maths. So if you typed a 2 in the binary box or a G in the hex box and the answer looks odd, that is why. It handles unsigned integers only: no minus sign, no decimal point, no two's complement interpretation, so for negatives convert the bit pattern you already have. All of it runs in the browser.