UTF-8 is a widely adopted variable-length character encoding scheme that uses 1 to 4 bytes to represent Unicode characters. UTF-8 can encode all characters defined in the Unicode standard, which currently supports over 143,000 characters.
One of UTF-8's design goals is compatibility with traditional ASCII encoding, enabling the first 128 characters (code points 0 to 127) to be encoded with a single byte. For characters with larger code points, UTF-8 increases the byte count as follows:
- Code points from 128 to 2047 use two bytes.
- Code points from 2048 to 65535 use three bytes.
- Code points from 65536 to 1114111 use four bytes.
This encoding scheme not only supports an extensive character set—including nearly all modern writing systems—but also effectively accommodates legacy data. In practical applications, this feature makes UTF-8 one of the most widely used encoding schemes in network and multilingual environments.