A code point is the number Unicode assigns to a character, written as U+ followed by hexadecimal digits. U+2665 is BLACK HEART SUIT. The code point is the character's permanent identity — it never changes, and it is what you check when two characters look the same but behave differently.
Reading U+ notation
The digits after U+ are hexadecimal, base sixteen, using 0-9 then A-F. At least four digits are written, with more for larger values: U+0041, U+2665, U+1F600. The prefix exists so the number is unmistakably a code point rather than an ordinary figure.
The same character, several notations
One character can be written many ways depending on context. U+2665 is decimal 9829, the HTML entity ♥ or ♥, the CSS escape \2665, and the JavaScript escape \u2665. All identify the same character; only the syntax differs according to what is parsing it.
Planes and the U+FFFF boundary
Unicode is organised into seventeen planes of 65,536 code points. The first, the Basic Multilingual Plane, holds almost everything used in everyday writing. Characters above U+FFFF sit in supplementary planes and include most emoji and the mathematical alphabets. That boundary matters in practice: supplementary characters need two units in UTF-16, so software that assumes one unit per character miscounts them, and font coverage above U+FFFF is noticeably thinner.
Code points are not bytes
A code point is an abstract number. How it is stored depends on the encoding. UTF-8 uses one to four bytes per code point; UTF-16 uses two or four. This is why a string can have a different length depending on whether you count characters or bytes, and why emoji so often break character counters.
Why you would look one up
Because appearance is not identity. The Greek capital Alpha and the Latin capital A are drawn identically in most fonts and are different characters that sort and search differently. Several near-identical dashes, quotes and spaces exist for historical reasons. When a character is going into an identifier, a filename, or anything compared by a machine, the code point is the only reliable way to know what you have.
References
Related tools and guides
Last updated September 2026 · Editorial policy · How we verify Unicode claims