What is text to binary conversion?
Text to binary conversion writes a text as the base-2 bytes a computer uses to store it. This tool encodes the text as UTF-8 and shows each byte as a group of eight ones and zeros. An English letter is one byte, so one group; an accented letter or emoji is two to four. The reverse mode turns those groups back into readable text.
Computers have no idea what an "H" is. They store the number 72, defined for that letter by the ASCII standard, and the bits 01001000 are that number written in binary. Unicode extends the same idea to every writing system, with ASCII as its first 128 codes.
How to use the converter
- Choose a Direction: Text → Binary or Binary → Text.
- Type or paste your input.
- Click Convert and copy the result.
In Binary → Text mode, separate each byte with a space or a line break. Groups can be up to 8 digits long and don't need leading zeros.
Worked example
Converting Hi! gives 01001000 01101001 00100001:
| Character | Decimal code | Binary |
|---|---|---|
| H | 72 | 01001000 |
| i | 105 | 01101001 |
| ! | 33 | 00100001 |
To read a binary group, add up the place values of its 1s. From the left, the eight positions are worth 128, 64, 32, 16, 8, 4, 2 and 1. 01001000 has 1s in the 64 and 8 positions, and 64 + 8 = 72, which is H.
Paste 01001000 01101001 00100001 back in with Binary → Text selected and you get Hi! again. 1001000 1101001 (no leading zeros) decodes to Hi as well.
Characters worth knowing
| Character | Binary | Note |
|---|---|---|
| Space | 00100000 | Code 32, the most common byte in English text |
| Line break | 00001010 | Code 10, line feed |
| 0 | 00110000 | Digits start at code 48, so the digit 0 isn't 00000000 |
| A | 01000001 | Uppercase letters run from 65 to 90 |
| a | 01100001 | Lowercase is uppercase plus 32, one extra bit |
That last row explains a classic trick: upper and lowercase ASCII letters differ by a single bit, the one worth 32.
Accents, symbols and emoji
Text is encoded as UTF-8, the encoding used by almost every web page and text file, so the output matches a byte-level dump of a UTF-8 file. The 128 ASCII characters are one byte each, and every other character takes two to four bytes:
| Input | Code point | UTF-8 bytes in binary |
|---|---|---|
| é | U+00E9 | 11000011 10101001 |
| € | U+20AC | 11100010 10000010 10101100 |
| 👍 | U+1F44D | 11110000 10011111 10010001 10001101 |
You can spot the structure in the bits. A lead byte starting 110 begins a two-byte character, 1110 a three-byte one and 11110 a four-byte one, and every continuation byte starts with 10. So café becomes five groups, not four: 01100011 01100001 01100110 11000011 10101001.
Reverse mode collects all the bytes and decodes them as UTF-8, so 11000011 10101001 comes back as é. If the bytes don't form valid UTF-8, it shows an error rather than guessing. Two common causes:
- A multi-byte character is cut short.
11000011on its own is the first half of é. - The binary came from a Latin-1 converter that writes é as the single byte
11101001. That byte isn't valid UTF-8 by itself.
For text you converted here, round trips are always exact.
Errors and fixes
| Input | What happens | Fix |
|---|---|---|
0100100001101001 |
Error: one 16-digit group | Add a space every 8 digits |
01001000,01101001 |
Error: comma isn't a separator | Use spaces or line breaks between groups |
010010000 |
Error: 9 digits | Check for a stray extra digit |
01001000 2 |
Error: not binary | Only 0 and 1 are allowed |
11000011 |
Error: not valid UTF-8 | Include every byte of a multi-byte character |
Related tools
- Base64 encoder: a compact way to carry bytes as text, used in email and data URLs.
- Base64 decoder: turn Base64 back into readable UTF-8 text.
- URL encoder: see the UTF-8 bytes of accented characters and emoji as %XX hex codes.
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