UTF-8

UTF-8_takes_over

Utf8webgrowth

== UTF-8 ==

UTF-8 (8-bit Unicode Transformation Format) is a variable-width character encoding used for electronic communication. Defined by RFC 3629, it is capable of encoding all 1,112,064 valid character code points in Unicode using one to four one-byte (8-bit) code units. UTF-8 is the dominant character encoding for the World Wide Web, accounting for more than 90% of all web pages.

History

UTF-8 was designed by Ken Thompson and Rob Pike in 1992. It was created to be backward compatible with ASCII and to avoid the complications of endianess and byte order marks that plagued other encodings like UTF-16 and UTF-32.

Encoding

UTF-8 encodes each of the 1,112,064 characters in the Unicode character set using one to four 8-bit bytes. The first 128 characters (US-ASCII) need one byte. The next 1,920 characters need two bytes to encode. This includes characters from most European languages and some non-European languages. Three bytes are needed for the rest of the Basic Multilingual Plane (which contains virtually all characters in common use, including most Chinese, Japanese, and Korean characters). Four bytes are needed for characters in other planes of Unicode, which include less common CJK characters, various historic scripts, and emoji.

Advantages

UTF-8 has several advantages over other encodings:

• It is backward compatible with ASCII.
• It does not suffer from endianess issues.
• It is efficient in terms of storage for ASCII characters.
• It is widely supported across different platforms and systems.

Usage

UTF-8 is the standard encoding for the World Wide Web and is used by most modern software applications. It is also the default encoding for XML and JSON files.

Related Pages

• Unicode
• ASCII
• UTF-16
• UTF-32
• Character encoding
• Endianness
• World Wide Web
• XML
• JSON