Text to Binary Converter

How to convert text to binary and back

1. Type or paste your text in the input box, or press Example to load the sample Hi 👋.
2. Leave Direction on Text → binary. The output shows one group of 8 digits per byte, and the line under it gives the total, such as 7 bytes in UTF-8.
3. Untick Space between bytes if you need one continuous string of zeros and ones instead of separate bytes.
4. To decode, switch Direction to Binary → text and paste the binary. Use as input moves the output into the input box, so you can switch the direction and check that a conversion goes back to the original.
5. Press Copy to copy the result.

How a character becomes binary

Computers store text as numbers. The tool first encodes your text as UTF-8 and then writes each byte in base 2, padded with leading zeros to 8 digits.

Take Hi. In UTF-8, H is byte 72 and i is byte 105. Writing those in base 2:

The eight places are worth 128, 64, 32, 16, 8, 4, 2 and 1 from left to right. A 1 means that value is included, so 01001000 is 64 + 8 = 72.

Uppercase and lowercase letters differ in exactly one bit, the one worth 32: A is 01000001 and a is 01100001. That is why Cat and cat produce different first bytes.

Accents, emoji and other characters

Plain English letters, digits, punctuation and spaces are one byte each, the same values as ASCII. Everything else takes two to four bytes, following the UTF-8 rules in RFC 3629: the first byte starts with 110, 1110 or 11110 to say how many bytes follow, and each following byte starts with 10.

A few things to know:

• Spaces and line breaks are characters too. A space is 00100000 and a line break is 00001010. The binary output stays on one line; the line break appears as its byte.
• The same-looking letter can have two encodings. An é typed as one character is 2 bytes, but e followed by a combining accent is 3 bytes (01100101 11001100 10000001). Both look identical on screen.
• Emoji can be several characters. 👍🏽 is a thumbs-up plus a skin-tone modifier, so it becomes 8 bytes.

A binary table that only lists ASCII cannot show these characters. Because this tool uses UTF-8 for everything, its output decodes back to exactly the text you started with.

How binary is read back into text

Under Binary → text the tool accepts binary in the formats people usually paste:

Unspaced binary that was wrapped over several lines also works, because every line is a multiple of 8 digits and is read 8 digits at a time:

0100100001101001
0100000101000010

decodes to HiAB.

The tool stops with a message, and an empty output, when the input cannot be read:

The last case happens when a byte that starts a multi-byte character is missing its continuation bytes, or when the binary was made with another encoding.

When people use it

• Computer science homework. Checking a hand conversion of a name or word into ASCII and binary, or seeing why é needs two bytes.
• Puzzles and escape rooms. Hiding a clue as zeros and ones, or decoding one. For other simple codes, try the Morse code translator or the Caesar cipher.
• Debugging encoding problems. When text shows up as é instead of é, looking at the actual bytes shows whether the text is UTF-8. The text to hex converter shows the same bytes in a shorter form that matches most developer tools.
• Spotting invisible characters. A zero-width space shows up as the bytes 11100010 10000000 10001011 between visible letters; the invisible character remover deletes them, and the guide to zero-width spaces explains where they come from.
• Counting storage. The byte count under the output is the size of the text in UTF-8, which is what database and API limits measured in bytes count. The character counter shows characters and bytes side by side.

Binary, hex and Base64

All three write the same UTF-8 bytes in different ways. Binary uses 8 digits per byte, hexadecimal uses 2 (48 69 for Hi), and Base64 packs every 3 bytes into 4 characters (SGk=), which is why it is used to send data through email and URLs. The Base64 encoder and the guide what is Base64 cover that format.

Questions