Hex to binary converter

Hex to binary 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 hex to binary

Replace each hex digit with its 4-bit binary value, keeping the leading zeros inside each group — hex 1 is 0001, not 1 — and join the groups in order. For AD: A → 1010, D → 1101, giving 1010 1101. Nothing is carried from one digit to the next, so a long hex number converts as easily as a short one.

Hex and binary side by side

The largest 16-bit value is FFFF in hex and 1111111111111111 in binary: 4 digits against 16. 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. Binary is what bit masks, flags and subnet masks are reasoned in: a /24 network mask is twenty-four 1 bits followed by eight 0 bits, 255.255.255.0 once written in decimal. In JavaScript and Python source, 173 is written 0xAD in hex and 0b10101101 in binary. 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 — hex on this page.

Other conversions

Going the other way? Binary to hex converter.

• Octal to binary
• Decimal to binary
• Hex to octal
• Hex to decimal

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