How text becomes binary
Every character has a numeric code. That number is written in base 2 and padded to eight digits, because one byte is eight bits. The letter H is code 72, which is 64 + 8, so its bits are 01001000. The letter i is code 105, or 01101001. Put together, Hi becomes 01001000 01101001.
Pair this with the binary to decimal calculator when you need the fuller picture.
How to use this converter
Type any text and read the space-separated binary below, with a note showing how many bytes and bits it took. Characters outside ASCII are first encoded as UTF-8, so a single emoji or accented letter may produce two to four groups rather than one. That matches how the text is actually stored in a file or sent over a network. To read binary back into words, use the binary to text calculator.
The output is grouped and space-separated so you can count bytes at a glance: an eight-character ASCII string gives eight groups and 64 bits. Everything runs in your browser, so the text you enter is never uploaded or stored.
Groups often move straight on to the Base64 encoder afterwards.
Character reference
A few codes worth recognising on sight:
| Character | Code | Binary |
|---|---|---|
| space | 32 | 00100000 |
| 0 | 48 | 00110000 |
| A | 65 | 01000001 |
| H | 72 | 01001000 |
| a | 97 | 01100001 |
| i | 105 | 01101001 |
For plain number conversion, see the decimal to binary calculator.
Two patterns are easy to spot once you know them. Every ASCII letter starts with 010 for uppercase and 011 for lowercase, and any group beginning with 11 is the first byte of a multi-byte UTF-8 character rather than a character on its own.
Frequently asked questions
- What is Hi in binary?
- It is 01001000 01101001, one 8-bit group for H (72) and one for i (105).
- Why are the groups exactly eight digits?
- One byte holds eight bits, and padding every group to eight digits keeps the output aligned and unambiguous.
- How are emoji handled?
- They are encoded as UTF-8 first, so a single emoji usually produces four 8-bit groups rather than one.
- Is uppercase different from lowercase?
- Yes. A is 65 (01000001) and a is 97 (01100001), a difference of exactly one bit.
- Is the text I convert uploaded anywhere?
- No. The conversion happens entirely in your browser, so nothing you type is transmitted or stored on a server. That makes it safe to convert private notes, keys or sample data.