Binary to Hex Converter

Split the binary number into groups of four bits, beginning at the right-hand end. Pad the leftmost group with zeros if it's short, then turn each group into one hex digit. For 1011011:

The result is 5B, which matches the converter. The common mistake is to group from the left (1011, then 011 padded on the right to 0110). That gives B6, which is the hex for 10110110, a different number.

Hex is a quarter of the length and still shows the bit pattern directly. A 16-bit mask such as 1111000011110000 becomes F0F0, which you can write in code as 0xF0F0 and still see which half of each byte is set. Long bit strings are also easier to compare by eye or read aloud in hex: a difference in one bit shows up as a different digit in one place.

• Spaces are fine. 0001 1111 is read as 00011111 and gives 1F.
• Leading zeros are dropped from the result. 00001111 gives F. For a full byte, write it as 0F.
• Don't type a 0b prefix. 0b1111 comes out as 0, since the b ends the number right after the leading zero.
• Only 0 and 1 are read. Any other character ends the number without an error message, so a stray 2 or a full stop truncates the input.
• The starting value isn't binary. The box is pre-filled with 42, so an error shows until you type your own bits.

The output uses capital letters and has no 0x prefix.