Editing Windows-1251 (section)

{{Short description|Windows character set for Cyrillic alphabet}}
{{Infobox character encoding
| name     = Windows-1251
| mime     = windows-1251
| image    = 
| caption  = 
| alias    = cp1251 ([[Code page]] 1251)
| by       = [[Microsoft]]
| standard = [[WHATWG]] Encoding Standard
| lang     = [[Russian language|Russian]], [[Ukrainian language|Ukrainian]], [[Belarusian language|Belarusian]], [[Bulgarian language|Bulgarian]], [[Serbian Cyrillic alphabet|Serbian Cyrillic]], [[Bosnian language#Alphabet|Bosnian Cyrillic]], [[Macedonian language|Macedonian]], [[Rotokas alphabet|Rotokas]], [[Rusyn language|Rusyn]], [[English language|English]]
| status   =
| extends  = <!-- Note: not related to ISO-8859-5 -->
| prev     = 
| next     = 
| encodes  = 
| classification = [[extended ASCII]], [[Windows-125x]]
| otherrelated = [[#Amiga variant|Amiga-1251]], [[#Kazakh variant|KZ-1048]], <br/>[[ISO-IR-111#Incorrect RFC 1345 code page|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 language|Russian]], [[Ukrainian language|Ukrainian]], [[Belarusian language|Belarusian]], [[Bulgarian language|Bulgarian]], [[Serbian Cyrillic alphabet|Serbian Cyrillic]], [[Macedonian language|Macedonian]] and other languages.

On the web, it is the second most-used single-byte character encoding (or third most-used character encoding overall), and most used of the single-byte encodings supporting Cyrillic. {{As of|2024|1}}, 0.3% of all [[website]]s use Windows-1251.<ref name="encoding">{{cite web|url=https://w3techs.com/technologies/history_overview/character_encoding|title=Historical trends in the usage of character encodings,  January 2024|access-date=2024-01-01}}</ref><ref>{{cite web|url=https://w3techs.com/faq|title=Frequently Asked Questions}}</ref> It's by far mostly used for Russian, while a small minority of Russian websites use it, with 94.6% of Russian (.ru) websites using [[UTF-8]],<ref>{{Cite web|title=Distribution of Character Encodings among websites that use .ru|url=https://w3techs.com/technologies/segmentation/tld-ru-/character_encoding|website=w3techs.com|access-date=2024-01-01}}</ref><!-- It's among the top used encodings for any country/language, [[EUC-KR]] is possibly higher, and Breton at 13.4% use of ISO-8859-1 has most use https://w3techs.com/technologies/segmentation/cl-br-/character_encoding for a single language. Windows-1251 is used by 4.7% of Russian language, as opposed to .ru websites which has higher stats. --><ref>{{Cite web|title=Distribution of Character Encodings among websites that use Russian|url=https://w3techs.com/technologies/segmentation/cl-ru-/character_encoding|access-date=2023-01-16|website=w3techs.com}}</ref><ref>{{Cite web|title=Distribution of Character Encodings among websites that use Russian Federation|url=https://w3techs.com/technologies/segmentation/sl-ru-/character_encoding|access-date=2021-11-05|website=w3techs.com}}</ref> and the legacy 8-bit encoding is distant second. In Linux, the encoding is known as cp1251.<ref>{{Cite web|url=http://man7.org/linux/man-pages/man7/cp1251.7.html|title=cp1251(7) - Linux manual page|website=man7.org|access-date=2018-07-01}}</ref>  [[IBM]] uses code page 1251 ([[CCSID]] 1251 and [[euro sign]] extended CCSID 5347) for Windows-1251.<ref>{{cite web|title=Code page 1251 information document|archive-url=https://web.archive.org/web/20160303215653/http://www-01.ibm.com/software/globalization/cp/cp01251.html|archive-date=2016-03-03|url=https://www-01.ibm.com/software/globalization/cp/cp01251.html}}</ref><ref>{{cite web|title=CCSID 1251 information document|archive-url=https://web.archive.org/web/20141129205237/http://www-01.ibm.com/software/globalization/ccsid/ccsid1251.html|archive-date=2014-11-29|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid1251.html}}</ref><ref>{{cite web|title=CCSID 5347 information document|archive-url=https://web.archive.org/web/20141129214513/http://www-01.ibm.com/software/globalization/ccsid/ccsid5347.html|archive-date=2014-11-29|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid5347.html}}</ref><ref>{{Citation|title=Code Page CPGID 01251 (pdf)|url=https://public.dhe.ibm.com/software/globalization/gcoc/attachments/CP01251.pdf|publisher=IBM}}</ref><ref>{{Citation|title=Code Page CPGID 01251 (txt)|url=https://public.dhe.ibm.com/software/globalization/gcoc/attachments/CP01251.txt|publisher=IBM}}</ref><ref>{{Citation|title=International Components for Unicode (ICU), ibm-1251_P100-1995.ucm|url=https://github.com/unicode-org/icu/blob/master/icu4c/source/data/mappings/ibm-1251_P100-1995.ucm|date=2002-12-03}}</ref><ref>{{Citation|title=International Components for Unicode (ICU), ibm-5347_P100-1998.ucm|url=https://github.com/unicode-org/icu/blob/master/icu4c/source/data/mappings/ibm-5347_P100-1998.ucm|date=2002-12-03}}</ref>

Windows-1251 and [[KOI8-R]] (or its [[Ukrainian language|Ukrainian]] variant [[KOI8-U]]) are much more commonly used than [[ISO 8859-5]] (which is used by less than 0.0004% of websites).<ref>{{Cite web|url=https://w3techs.com/technologies/overview/character_encoding/all|title=Usage Statistics of Character Encodings for Websites|website=w3techs.com|language=en |url-status=live |archive-url=https://archive.today/20120530032500/http://w3techs.com/technologies/overview/character_encoding/all |archive-date=2012-05-30}}</ref> In contrast to [[Windows-1252]] and [[ISO 8859-1]], Windows-1251 is not closely related to ISO 8859-5.

[[Unicode]] (e.g. UTF-8) 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, of 436 Cyrillic letters/code points, including for [[Old Cyrillic]], and how single-byte character encodings, such as Windows-1251 and [[KOI8-R]], cannot provide this, see [[Cyrillic script in Unicode]].)