Binary to Text Translator: Decode 0s and 1s

How to translate binary to text

1. Paste the binary into Input · Binary. Bytes can be separated by spaces, new lines, commas, semicolons or |, or not separated at all.
2. The text appears in Output · Text as you type.
3. If you see �, the bits are not valid UTF-8. Try another Charset under the output, such as ISO-8859-1.
4. Copy output copies the text. Text → Binary above the tool switches direction, as does Text to Binary.

How to read binary by hand

Each group of 8 bits is one byte. Give every position a value, from 128 on the left down to 1 on the right, and add up the positions that hold a 1:

01001000 is 64 + 8 = 72, and character 72 in ASCII is H. 01101001 is 64 + 32 + 8 + 1 = 105, which is i.

You rarely need the arithmetic for letters, because ASCII is laid out in a pattern. The first three bits say what kind of character it is, and for letters the last five bits are the position in the alphabet:

So 01000011 ends in 00011, which is 3, the third letter: C. Uppercase and lowercase differ in a single bit, the third from the left.

Formats the translator accepts

All of them decode to Hi. A group shorter than 8 bits is read as one byte, which is why the 7-bit version works. If any group is longer than 8 bits, the tool joins all the bits into one string and cuts that into bytes instead. Anything other than 0, 1 and separators stops the conversion with the position of the bad character; the Show button next to the message selects it in the input.

Binary that is not plain ASCII

ASCII bytes always start with 0. A byte starting with 1 belongs to a multi-byte UTF-8 character, and its leading bits tell you how long the sequence is:

If you decode these one byte at a time you get junk such as é. Keep the bytes together and leave Charset on UTF-8.

From binary to Base64

Binary, hex and Base64 are all ways of writing the same bytes. Binary uses 8 characters per byte, hex 2, Base64 about 1.33, so Base64 is what systems use to move binary data through text: email attachments, JSON fields, data URIs. To turn your bits into Base64 directly, use Binary to Base64. To see the bits inside a Base64 string, use Base64 to Binary; how Base64 works shows how it regroups those bits 6 at a time.

Binary to text in code

bits = "01001000 01101001"
bytes(int(b, 2) for b in bits.split()).decode("utf-8")   # 'Hi'

const bits = "01001000 01101001";
new TextDecoder().decode(Uint8Array.from(bits.split(" "), b => parseInt(b, 2)));   // 'Hi'

Both assume the groups are separated by single spaces; the tool above is more forgiving about the input format.

FAQ