Binary to hex converter

Binary to hex table

The last rows are the largest 32-bit and 64-bit unsigned values. The second is past the point where ordinary JavaScript numbers start rounding; the table and the converter above both compute with BigInt, so every digit is exact.

How to convert binary to hex

Split the binary number into groups of 4 bits, starting from the right, and pad the leftmost group with zeros if it comes up short. Each group is exactly one hex digit, because 16 = 2⁴: no carrying and no arithmetic across groups, just a lookup of 16 possible patterns. For 10101101: 1010 1101; then 1010 → A, 1101 → D — so 10101101 in binary is AD in hex.

Binary and hex side by side

The largest 16-bit value is 1111111111111111 in binary and FFFF in hex: 16 digits against 4. Every hex digit is exactly 4 bits, so the lengths stay in a fixed ratio and any stretch of digits can be converted without looking at its neighbours. Hex is the usual way to write bytes — colours like #FF8800, memory addresses, hashes, escape sequences — because a byte is always exactly two hex digits. In JavaScript and Python source, 173 is written 0b10101101 in binary and 0xAD in hex. Paste a prefixed number into the converter and it switches to the matching base; a number with no prefix is read in the selected base — binary on this page.

Other conversions

Going the other way? Hex to binary converter.

• Binary to octal
• Binary to decimal
• Octal to hex
• Decimal to hex

Or open the full number base converter and see a number in all four bases at once.