Unicode

ASCII was a great start. But 128 codes were nowhere near enough for the world's writing systems, symbols, and emoji.

The problem wasn't the keyboard. It was the codebook.

Basic ASCII only had codes 0–127. That worked for English letters, digits, punctuation, and control codes — but not ñ, 中, ع, Ω, 😀, and thousands of other characters people actually use.

Try one character

Character A

Basic ASCII can store this.

→

Unicode code point U+0041

→

UTF-8 bytes 1 byte

Unicode decides which code point a character gets. UTF-8 is one way to turn that Unicode character into actual bytes for storage or transmission.

Some characters need more bytes than others.

UTF-8 keeps basic ASCII compact: those first 128 characters still use one byte. Other Unicode characters can use more.

U+00411 UTF-8 byte

U+00F12 UTF-8 bytes

中

U+4E2D3 UTF-8 bytes

😀

U+1F6004 UTF-8 bytes

ASCII lives inside Unicode. The first 128 Unicode code points match ASCII, so A is still 65 / U+0041.

ASCII or Unicode?

Decide whether basic ASCII can represent the character shown.

Can basic ASCII store this character?

0 correct · 0 answered

ASCII was a small shared codebook. Unicode became the much bigger one. And UTF-8 shows how those Unicode characters can be stored as bytes.