How text becomes binary
A computer stores each character as a number. For plain English text the numbers come from ASCII, which gives every letter, digit and common symbol a code from 0 to 127.[1][2]
That code is then written in base 2. RFC 20 describes the code as seven bits placed in an 8-bit byte whose top bit is always 0, which is why every ASCII letter in binary starts with 0.[3]
Characters outside ASCII, such as é, ñ, Chinese characters and emoji, are written with UTF-8. UTF-8 keeps every ASCII code in a single byte and uses two, three or four bytes for everything else.[4][5]
Convert a word by hand
- Write down the word one character at a time. A space counts as a character too.
- Look up each character’s number in the ASCII table. Capital C is 67, small a is 97 and small t is 116.
- Write each number in base 2 using eight digits. Add zeros on the left until there are eight.
- Put the bytes in order with a space between them so they are easy to read.
Worked example: Cat
- Text
- Cat
- Binary
- 01000011 01100001 01110100
| Character | Code point | Bytes in binary |
|---|---|---|
| C | U+0043 | 01000011 |
| a | U+0061 | 01100001 |
| t | U+0074 | 01110100 |
- C is 67, which is 64 + 2 + 1, so its byte is 01000011.
- Small a and t start with 011, while capital C starts with 010. A capital letter and its small letter differ in one bit.
Common words in binary
| Word | Binary |
|---|---|
| Yes | 01011001 01100101 01110011 |
| No | 01001110 01101111 |
| Hello | 01001000 01100101 01101100 01101100 01101111 |
| Love | 01001100 01101111 01110110 01100101 |
| Thanks | 01010100 01101000 01100001 01101110 01101011 01110011 |
Every word in this table uses only ASCII letters, so the number of bytes equals the number of letters. Add an accented letter or an emoji and the byte count grows faster than the letter count.[4]
Questions about text to binary
Does text to binary work for any language?
Yes. UTF-8 can store every character in Unicode, so Greek, Arabic, Hindi, Chinese and emoji all convert. Only English letters, digits and common symbols stay at one byte each.
Why does a space have a binary code?
A space is a character like any other. Its ASCII code is 32, so it becomes 00100000. Each space between words shows up as its own byte.
Can I convert a whole paragraph?
Yes. The converter takes up to 20,000 characters at once and keeps line breaks. A line break is the Line Feed character, code 10, which is 00001010.
Sources, last checked October 12, 2026
- Glossary of Unicode Terms (Unicode Consortium)
The American Standard Code for Information Interchange, a 7-bit coded character set for information interchange.
The set of 128 Unicode characters from U+0000 to U+007F, including control codes as well as graphic characters.
- RFC 20: ASCII format for Network Interchange (IETF, 1969)
For concreteness, we suggest the use of standard 7-bit ASCII embedded in an 8 bit byte whose high order bit is always 0.
- RFC 3629: UTF-8, a transformation format of ISO 10646 (IETF, 2003)
US-ASCII characters are encoded in one octet having the normal US-ASCII value, and any octet with such a value can only stand for a US-ASCII character, and nothing else.
In UTF-8, characters from the U+0000..U+10FFFF range (the UTF-16 accessible range) are encoded using sequences of 1 to 4 octets.
The only octet of a "sequence" of one has the higher-order bit set to 0, the remaining 7 bits being used to encode the character number.