How it works
Text is encoded as UTF-8 and each byte is written as eight bits. Decoding reads the bits eight at a time and checks that the bytes form valid UTF-8 before showing text.
A → 01000001 · 한 → 11101101 10010101 10011100
- Spaces, tabs, new lines and underscores in the binary input are ignored.
- The number of digits must be a multiple of 8.
- Bytes that are not valid UTF-8 are rejected instead of showing garbled characters.
Worked examples
| Text | Binary | Bytes |
|---|---|---|
| A | 01000001 | 1 |
| a | 01100001 | 1 |
| 0 | 00110000 | 1 |
| space | 00100000 | 1 |
| 한 | 11101101 10010101 10011100 | 3 |
| 😀 | 11110000 10011111 10011000 10000000 | 4 |
ASCII letters take one byte, most accented letters and Greek or Cyrillic take two, Korean, Japanese and Chinese characters usually take three, and emoji take four.
Tips
- When decoding, keep the groups of eight so a missing bit is easy to spot.
- Binary is base 2: each position is worth 1, 2, 4, 8, 16, 32, 64 or 128 from the right.
- To convert whole numbers between bases (not text), use the number base converter instead.
Standards and sources
- RFC 3629 · UTF-8, a transformation format of ISO 10646 (IETF)
- The Unicode Standard · Unicode Consortium
Last reviewed October 27, 2026
Frequently asked questions
Why 8 bits per group?
One byte is 8 bits, and UTF-8 writes each character as one to four bytes. Grouping by eight makes the bytes easy to read.
Why does one Korean character become three groups?
Non-Latin scripts need more bytes: Korean syllables take 3 bytes, most accented letters 2, and emoji 4.
Can I paste binary without spaces?
Yes. Spaces, tabs, new lines and underscores are ignored, but the number of digits must be a multiple of 8.
Is the conversion reversible?
Yes for valid UTF-8. Bytes that are not valid UTF-8 are rejected instead of showing garbled text.