Binary to Text

Binary to text decoder

The binary to text converter reads groups of 0s and 1s as bytes and decodes the bytes as UTF-8 text. Use it to decode binary messages, check homework, solve puzzles or inspect bit patterns from a program.

Accepted input

• Groups separated by spaces, line breaks or commas: 01001000 01101001.
• One unbroken string whose length is a multiple of 8: 0100100001101001. It is split into bytes automatically.
• Groups shorter than eight bits are allowed when separated, so 1001000 is read as 72, just like 01001000.

Any character other than 0, 1, whitespace and commas produces an error, as does a group whose value is larger than one byte (over 255).

Example

Input:

01001000 01101001 00100000 01110100 01101000 01100101 01110010 01100101 00100001

Output:

Hi there!

Each group of eight bits became one character here because the message is plain ASCII. Accented letters and emoji would take two to four groups each.

How to decode a byte by hand

Write the place values 128, 64, 32, 16, 8, 4, 2, 1 above the eight bits and add the values where there is a 1. For 01101000 that is 64 + 32 + 8 = 104, the code for “h”. The tool does this for every byte and then applies UTF-8 decoding, so multi-byte characters such as “é” (11000011 10101001) come out correctly.

Troubleshooting

• “Binary input without separators must be a multiple of 8 bits”. A digit is missing or extra somewhere. Add spaces between bytes to find it.
• Replacement characters (�). The bytes are not valid UTF-8, often because a bit was flipped or a byte is missing in a multi-byte character.
• 7-bit ASCII puzzles. Some puzzles use 7-bit groups without separators. Add spaces every 7 digits so the tool reads each group separately.

In Python the same decoding is bytes(int(g, 2) for g in s.split()).decode(), handy when you need it inside a script.

To convert text into binary, use Text to Binary. If the binary represents a number rather than text, the Binary to Decimal converter is what you need, and Binary to Base64 re-encodes the bytes in Base64. Everything runs in your browser.

Patterns that help you check the bits

ASCII was laid out so that the first bits of a byte tell you what kind of character it is. That makes it easy to spot a damaged or misaligned group before decoding:

Upper- and lowercase forms of a letter differ in a single bit: A is 01000001 and a is 01100001. If a message decodes into symbols instead of letters, one group probably has a missing or extra digit, which shifts every following byte.