UTF-8 is a variable-length character encoding standard used for electronic communication¹. It is based on the Unicode Standard, which is a universal system for representing characters from different languages and scripts².

UTF-8 can encode all 1,112,064 valid Unicode code points using one to four bytes (8-bit units) per character¹. The first 128 characters of Unicode, which correspond to the ASCII characters, are encoded using a single byte with the same binary value as ASCII¹. This means that valid ASCII text is also valid UTF-8-encoded text.

UTF-8 has several advantages over other encodings:

• It is backward compatible with ASCII, which is widely used in web protocols, programming languages, and text files¹.

• It can represent any character in the Unicode standard, which covers most of the world's writing systems².

• It is self-synchronizing, which means that it can recover from errors or data loss by resuming at the next valid code point¹.

• It is efficient, as it uses fewer bytes for common characters and avoids wasting space with padding or byte order marks³.

UTF-8 is the dominant encoding for the World Wide Web and internet technologies, accounting for 98.1% of all web pages as of 2024¹. It is also widely supported by modern operating systems, software applications, and standards such as JSON¹.

To use UTF-8 encoding in HTML documents, you can specify the charset attribute in the tag:

To use UTF-8 encoding in other text files, such as source code or data files, you can save them with UTF-8 encoding in your text editor or IDE. Alternatively, you can use a byte order mark (BOM) at the beginning of the file to indicate the encoding. However, some applications may not recognize or handle the BOM correctly, so it is generally recommended to avoid using it unless necessary³.