Binary Converter
Convert numbers between binary, decimal, hexadecimal, and octal with linked live fields — plus text to UTF-8 binary or hex bytes and back.
Processed locally in your browser — nothing is uploaded.
Edit any field and the others update. Prefixes (0b, 0o, 0x), spaces, and _ separators are accepted; values of any size work thanks to BigInt.
About Binary Converter
Four linked fields — binary, octal, decimal, and hexadecimal — stay in sync as you type in any of them. Values are handled with BigInt, so numbers far beyond 2^53 convert exactly. Prefixes (0b, 0o, 0x), spaces, and underscore separators are accepted.
Text mode converts a string to its UTF-8 bytes shown as binary or hex, and decodes byte sequences back to text, with clear errors for invalid UTF-8.
Common uses
- Read a hex constant or bitmask from code as decimal
- Convert file permission or flag values between bases
- Inspect what bytes a string actually encodes to
Example
Input
255 (decimal)
Output
0b11111111 · 0o377 · 0xff