|MIME / IANA||windows-1251|
|Alias(es)||cp1251 (Code page 1251)|
|Language(s)||English, Russian, Ukrainian, Belarusian, Bulgarian, Serbian Cyrillic, Macedonian|
|Standard||WHATWG Encoding Standard|
|Classification||extended ASCII, Windows-125x|
|Other related encoding(s)||Amiga-1251, KZ-1048, |
RFC 1345's "ECMA-Cyrillic"
Windows-1251 is an 8-bit character encoding, designed to cover languages that use the Cyrillic script such as Russian, Bulgarian, Serbian Cyrillic and other languages. It is the most widely used encoding for the Bulgarian, Serbian and Macedonian languages. As of September 2020 , 1.0% of all (and 0.6% of top-1000) websites use Windows-1251. However, it is used by 10.6% of Russian (.ru) websites, where it is the second most popular choice after UTF-8. In Linux, the encoding is known as cp1251.IBM uses code page 1251 (CCSID 1251 and euro sign extended CCSID 5347) for Windows-1251.
Windows-1251 and KOI8-R (or its Ukrainian variant KOI8-U) are much more commonly used than ISO 8859-5 (which is "used by less than 0.1% of websites"). In contrast to Windows-1252 and ISO 8859-1, Windows-1251 is not closely related to ISO 8859-5.
Unicode is preferred to Windows-1251 or other Cyrillic encodings in modern applications, especially on the Internet, making UTF-8 the dominant encoding for web pages. (For further discussion of Unicode's complete coverage and how single-byte character encodings, such as Windows-1251 and KOI8-R, cannot provide this, see Cyrillic script in Unicode.)
The following table shows Windows-1251. Each character is shown with its Unicode equivalent and its decimal code.
Letter Number Punctuation Symbol Other Undefined
An altered version of Windows-1251 was standardised in Kazakhstan as Kazakh standard STRK1048, and is known by the label
KZ-1048. It differs in the rows shown below:
|MIME / IANA||Amiga-1251|
|Based on||Windows-1251, ISO-8859-1, ISO-8859-15|
Russian Amiga OS systems used a version of code page 1251 which matches Windows-1251 for the Russian subset of the Cyrillic letters, but otherwise mostly follows ISO-8859-1. This version is known as Amiga-1251, under which name it is registered with the IANA.