UTF-8 (Unicode Transformation Format - 8-bit) is a widely used character encoding standard that represents text in computers, enabling compatibility with many languages and symbols. It is part of the Unicode standard and is designed to encode all possible characters (or code points) in Unicode.
Key Features:
1. Variable-Length Encoding:
• Uses 1 to 4 bytes per character.
• Efficient for texts containing mostly ASCII characters, as these only require 1 byte.
2. Backward Compatibility:
• ASCII characters (code points 0–127) are encoded identically in UTF-8, making it compatible with older systems.
3. Universal Support:
• Can represent over 1 million characters, supporting virtually all languages, symbols, and emoji.
4. Error Detection:
• Invalid byte sequences can often be identified, making it robust for data transmission.
Encoding Structure:
Number of Bytes Byte Format Range of Code Points
1 Byte 0xxxxxxx U+0000 to U+007F
2 Bytes 110xxxxx 10xxxxxx U+0080 to U+07FF
3 Bytes 1110xxxx 10xxxxxx 10xxxxxx U+0800 to U+FFFF
4 Bytes 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx U+10000 to U+10FFFF
Example:
• ASCII “A”:
• Unicode: U+0041
• UTF-8: 0x41 (1 byte)
• Euro symbol (€):
• Unicode: U+20AC
• UTF-8: 0xE2 0x82 0xAC (3 bytes)
• Emoji (😀):
• Unicode: U+1F600
• UTF-8: 0xF0 0x9F 0x98 0x80 (4 bytes)
Benefits of UTF-8:
• Compact for common characters (like ASCII).
• Supports all Unicode characters.
• Widely adopted across the web, operating systems, and programming languages.
It is the default encoding for web content and is considered the de facto standard for modern text processing.