Hex ↔ Binary converter

Type a number in any base to see it in the others, or turn text into bytes.

Hex ↔ Binary

What does it do?

It has two modes:

Numbers: type a value in decimal, hexadecimal, binary or octal and see it in all the others at once. Negative numbers and numbers of any size are supported.
Text ↔ bytes: turns text into its UTF-8 bytes written in hex, binary or decimal, and back. Handy for protocols, network dumps or CTF challenges.

Quick reference

Decimal	Hex	Binary	Octal
10	`0xA`	`0b1010`	`0o12`
255	`0xFF`	`0b1111 1111`	`0o377`
4096	`0x1000`	`0b1 0000 0000 0000`	`0o10000`

Text example

Hola in UTF-8 is 48 6f 6c 61 in hex, or 01001000 01101111 01101100 01100001 in binary.

Frequently asked questions

›Is there a size limit?

No practical one: numbers are handled as BigInt, so 64-bit values, hashes or 256-bit keys convert exactly, without the precision loss of regular JavaScript numbers.

›Can I paste numbers with a prefix like 0xFF?

Yes. 0x, 0b and 0o prefixes are recognised in any field and the value is moved to the right base. Underscores and spaces used as separators are ignored.

›How is text converted to binary?

The text is encoded as UTF-8 and every byte is written in the chosen base, so an accent or an emoji takes two to four bytes.