ASCII to Binary Converter

ASCII gives each English letter, digit, sign and control character a number from 0 to 127: A is 65, a is 97 and a space is 32. In binary these numbers are written with eight digits, one byte each, so A is 01000001 and Hi is 01001000 01101001. Type or paste text into the first field and the binary code appears as you type, byte by byte. Choose ASCII under “Encoding” to keep to the 128 ASCII characters: anything outside them is listed under the result. With UTF-8, the default, every character works, and letters such as é or Ж take two bytes, emoji four.

Under “Separator” choose a space, nothing, a new line or a comma between the bytes. UTF-16 and the older code pages of many languages are also in “Encoding”, and “Unicode code points” writes each character as the binary number of its code point. “Open a file” turns a whole file of up to 1 MB into binary. “Swap” turns binary code back into text, so you can check the result or read a message someone sent you; in that direction, bytes written without spaces are understood too. Everything runs in your browser.