What is UTF-8?

Answer 1

UTF-8 (Unicode Transformation Format – 8-bit) is the most widely used way to encode text as bytes so computers can store and transmit it.

It can represent essentially all Unicode characters—English letters, Arabic, Chinese, emoji, mathematical symbols, and more. Each character uses 1 to 4 bytes:

Character type Typical bytes Example

Basic ASCII 1 A, 7, !

Many accented/other scripts 2 é, Ω

Many Asian characters 3 中, 日

Emoji and some symbols 4 😀, 🚀

For example, the text Hello is encoded in UTF-8 as the bytes:

48 65 6C 6C 6F

Those are hexadecimal byte values. Because UTF-8 was designed to be compatible with ASCII, ordinary English ASCII text has exactly the same byte representation in both.

The important distinction is: Unicode defines characters and their numbers (code points); UTF-8 defines how those numbers are represented as bytes.

For example, A has Unicode code point U+0041, and UTF-8 stores it as the single byte 0x41. 😀 is U+1F600, and UTF-8 stores it as four bytes: F0 9F 98 80.