Characters, code points, bytes: why ๐จโ๐ฉโ๐ง is 1, 5 or 18
KankanCharacter counterOpen
All of the numbers are right; they measure different things. ๐จโ๐ฉโ๐ง is 1 character as people see it, 5 Unicode code points, 8 UTF-16 code units and 18 bytes in UTF-8.
The pieces inside one emoji
The family emoji is three emoji glued together with an invisible joiner (ZWJ).
That is 5 code points. Written in UTF-16 they take 8 units, and in UTF-8 they take 18 bytes. On screen it fills one space, so to a reader it is 1 character.
Counted four ways
Counted with the โtaken apartโ panel in Kankan.
| Text | Characters | Code points | UTF-16 units | UTF-8 bytes |
|---|---|---|---|---|
| a | 1 | 1 | 1 | 1 |
| รฉ (one code point) | 1 | 1 | 1 | 2 |
| รฉ (e plus a combining accent) | 1 | 2 | 2 | 3 |
| ๐ | 1 | 1 | 2 | 4 |
| ๐๐ฝ (thumb plus skin tone) | 1 | 2 | 4 | 8 |
| ๐บ๐ธ (U plus S) | 1 | 2 | 4 | 8 |
| ๐จโ๐ฉโ๐ง | 1 | 5 | 8 | 18 |
| ๐ด๓ ง๓ ข๓ ฅ๓ ฎ๓ ง๓ ฟ (flag of England) | 1 | 7 | 14 | 28 |
What each number measures
- Characters are what a reader would point at and call one letter or one emoji. Unicode calls them grapheme clusters, and the rules are in UAX #29. This is what the Kankan counters report.
- Code points are the numbered entries in Unicode. Combining accents, skin tones and joiners are code points of their own, which is how one visible character becomes several.
- UTF-16 units are what JavaScript and several other languages count when you ask for the length of a string. A form that validates length that way sees ๐จโ๐ฉโ๐ง as 8.
- Bytes are what gets stored or sent. UTF-8 uses 1 to 4 bytes per code point.
The same letter, two spellings
รฉ can be stored as one code point, or as a plain e followed by a combining accent. Both look identical. They differ in every column of the table except the first, and a search for one may not find the other. Software that cares usually normalises text to one form before counting. The twitter-text rules X uses do: either spelling counts as 1 there.
Which number does a limit use?
It depends on who set the limit, and the label rarely says. If an emoji uses up a limit faster than you expect, the form is counting units or bytes rather than characters. Two limits are documented well enough to work out exactly: X uses a weighted length, and SMS counts 7-bit slots or UTF-16 units.
Tap any character to see its pieces.
Open the character counterFound a mistake, or a rule that has changed? Email contact@lumenlab.page. We check it, fix it and put the new date on this guide.