Hex to Binary Converter

Each hexadecimal digit is exactly four binary digits, a group called a nibble. F is 1111, A is 1010, 8 is 1000 and 0 is 0000, so you can translate a value one digit at a time and concatenate the nibbles.

Binary numbers drop leading zeros, so hex 5 becomes 101 rather than 0101. Turn on 'Pad to 4-bit groups' and the tool left-pads the whole result to the next multiple of four bits, so 5 becomes 0101 and every nibble keeps its width.

It aligns to nibbles, meaning multiples of four bits, not eight. Hex value 1F pads to 00011111 (eight bits, which is also a byte here), but a three-nibble value pads to twelve bits rather than sixteen. If you need whole bytes, feed input that is a whole number of byte pairs.

No. The 0x or 0X prefix is optional and case-insensitive, so FF, 0xFF and 0XFF all produce 11111111. Whitespace between digits is removed too, which is why grouped input like DE AD BE EF converts cleanly.

Yes. Conversion uses JavaScript BigInt, so there is no fixed width limit and no floating-point rounding. Long hashes, 128-bit UUIDs and larger integers convert exactly.

Yes. Digits a through f and A through F are treated the same, so deadbeef and DEADBEEF give identical binary output.

Anything outside 0-9 and a-f triggers an 'Invalid hexadecimal' message in red under the input, and the binary box stays empty until you fix it. Letters like g through z, punctuation and a stray minus sign all count as invalid.

An empty input, or one that is only spaces and a 0x prefix, returns an empty binary output rather than an error. Nothing is shown until there is at least one valid hex digit to convert.

No. The conversion runs entirely in your browser with client-side JavaScript, so the hex you paste never leaves your device. The optional JSON API is separate and only runs when you call it directly.