An incomplete sphere made of large, white, jigsaw puzzle pieces. Each puzzle piece contains one glyph from a different writing system, with each glyph written in black.
The Wikipedia wordmark which displays the name Wikipedia, written in all caps. The W and the A are the same height and both are taller than the other letters, which are also all the same height.
The , a globe featuring glyphs from various writing systems
Main page of the English Wikipedia
Main Page of the English Wikipedia on July 23, 2018
Type of site
Online encyclopedia
Available in309 languages
Country of originUnited States
OwnerWikimedia Foundation
Created byJimmy Wales
Larry Sanger[1] Edit this at Wikidata
Alexa rankNegative increase 10 (Global, January 2020)[2]
RegistrationOptional[note 1]
Users>315,147 active users[note 2] and >85,634,144 registered users
1,145 administrators (English)
LaunchedJanuary 15, 2001; 19 years ago (2001-01-15)
Current statusActive
Content license
CC Attribution / Share-Alike 3.0
Most text is also dual-licensed under GFDL; media licensing varies
Written inLAMP platform[3]

Wikipedia (ə/ (About this soundlisten) PEE-dee-ə or ə/ (About this soundlisten) PEE-dee-ə) is a multilingual online encyclopedia created and maintained as an open collaboration project[4] by a community of volunteer editors using a wiki-based editing system.[5] It is the largest and most popular general reference work on the World Wide Web,[6][7][8] and is one of the most popular websites ranked by Alexa as of January 2020.[9] It features exclusively free content and no commercial ads, and is owned and supported by the Wikimedia Foundation, a non-profit organization funded primarily through donations.[10][11][12][13]

Wikipedia was launched on January 15, 2001, by Jimmy Wales and Larry Sanger.[14] Sanger coined its name,[15][16] as a portmanteau of "wiki" (the Hawaiian word for "quick"[17]) and "encyclopedia". Initially an English-language encyclopedia, versions of Wikipedia in other languages were quickly developed. With at least 5,998,694 articles,[note 3] the English Wikipedia is the largest of the more than 290 Wikipedia encyclopedias. Overall, Wikipedia comprises more than 40 million articles in 301 different languages[18] and by February 2014 it had reached 18 billion page views and nearly 500 million unique visitors per month.[19]

In 2005, Nature published a peer review comparing 42 hard science articles from Encyclopædia Britannica and Wikipedia and found that Wikipedia's level of accuracy approached that of Britannica,[20] although critics suggested that it might not have fared so well in a similar study of a random sampling of all articles or one focused on social science or contentious social issues.[21][22] The following year, Time magazine stated that the open-door policy of allowing anyone to edit had made Wikipedia the biggest and possibly the best encyclopedia in the world, and was a testament to the vision of Jimmy Wales.[23]

Wikipedia has been criticized for exhibiting systemic bias, for presenting a mixture of "truth, half truth, and some falsehoods",[24] and for being subject to manipulation and spin in controversial topics.[25] Wikipedia has been criticized for gender bias, particularly on its English-language site, where the dominant majority of editors are male. However, Edit-a-thons have been held to encourage female editors and increase the coverage of women's topics.[26][27] Facebook announced that by 2017 it would help readers detect fake news by suggesting links to related Wikipedia articles. YouTube announced a similar plan in 2018.[28]


Jimmy Wales and Larry Sanger


Logo reading " the free encyclopedia" in blue with large initial "N"
Wikipedia originally developed from another encyclopedia project called Nupedia

Other collaborative online encyclopedias were attempted before Wikipedia, but none were as successful.[29] Wikipedia began as a complementary project for Nupedia, a free online English-language encyclopedia project whose articles were written by experts and reviewed under a formal process.[30] It was founded on March 9, 2000, under the ownership of Bomis, a web portal company. Its main figures were Bomis CEO Jimmy Wales and Larry Sanger, editor-in-chief for Nupedia and later Wikipedia.[31][32] Nupedia was initially licensed under its own Nupedia Open Content License, but even before Wikipedia was founded, Nupedia switched to the GNU Free Documentation License at the urging of Richard Stallman.[33] Wales is credited with defining the goal of making a publicly editable encyclopedia,[34][35] while Sanger is credited with the strategy of using a wiki to reach that goal.[36] On January 10, 2001, Sanger proposed on the Nupedia mailing list to create a wiki as a "feeder" project for Nupedia.[37]

Launch and early growth

The domains and were registered on January 12, 2001[38] and January 13, 2001[39] respectively, and Wikipedia was launched on January 15, 2001,[30] as a single English-language edition at,[40] and announced by Sanger on the Nupedia mailing list.[34] Wikipedia's policy of "neutral point-of-view"[41] was codified in its first few months. Otherwise, there were relatively few rules initially and Wikipedia operated independently of Nupedia.[34] Originally, Bomis intended to make Wikipedia a business for profit.[42]

The Wikipedia Page on December 17, 2001

Wikipedia gained early contributors from Nupedia, Slashdot postings, and web search engine indexing. Language editions were also created, with a total of 161 by the end of 2004.[43] Nupedia and Wikipedia coexisted until the former's servers were taken down permanently in 2003, and its text was incorporated into Wikipedia. The English Wikipedia passed the mark of two million articles on September 9, 2007, making it the largest encyclopedia ever assembled, surpassing the 1408 Yongle Encyclopedia, which had held the record for almost 600 years.[44]

Citing fears of commercial advertising and lack of control in Wikipedia, users of the Spanish Wikipedia forked from Wikipedia to create the Enciclopedia Libre in February 2002.[45] These moves encouraged Wales to announce that Wikipedia would not display advertisements, and to change Wikipedia's domain from to[46] Brion Vibber applied the change on August 15, 2002.[47]

Though the English Wikipedia reached three million articles in August 2009, the growth of the edition, in terms of the numbers of new articles and of contributors, appears to have peaked around early 2007.[48] Around 1,800 articles were added daily to the encyclopedia in 2006; by 2013 that average was roughly 800.[49] A team at the Palo Alto Research Center attributed this slowing of growth to the project's increasing exclusivity and resistance to change.[50] Others suggest that the growth is flattening naturally because articles that could be called "low-hanging fruit"—topics that clearly merit an article—have already been created and built up extensively.[51][52][53]

A promotional video of the Wikimedia Foundation that encourages viewers to edit Wikipedia, mostly reviewing 2014 via Wikipedia content

In November 2009, a researcher at the Rey Juan Carlos University in Madrid found that the English Wikipedia had lost 49,000 editors during the first three months of 2009; in comparison, the project lost only 4,900 editors during the same period in 2008.[54][55] The Wall Street Journal cited the array of rules applied to editing and disputes related to such content among the reasons for this trend.[56] Wales disputed these claims in 2009, denying the decline and questioning the methodology of the study.[57] Two years later, in 2011, Wales acknowledged the presence of a slight decline, noting a decrease from "a little more than 36,000 writers" in June 2010 to 35,800 in June 2011. In the same interview, Wales also claimed the number of editors was "stable and sustainable".[58] A 2013 article titled "The Decline of Wikipedia" in MIT's Technology Review questioned this claim. The article revealed that since 2007, Wikipedia had lost a third of its volunteer editors, and those still there have focused increasingly on minutiae.[59] In July 2012, The Atlantic reported that the number of administrators is also in decline.[60] In the November 25, 2013, issue of New York magazine, Katherine Ward stated "Wikipedia, the sixth-most-used website, is facing an internal crisis".[61]


Map is showing how many articles of each European language there were as of January 2019. 1 square represents 1000 articles. Languages with less than 1000 articles are represented with one square. Languages are grouped by language family and each language family is presented by a separate colour.

In January 2007, Wikipedia entered for the first time the top-ten list of the most popular websites in the US, according to comScore Networks. With 42.9 million unique visitors, Wikipedia was ranked number 9, surpassing The New York Times (#10) and Apple (#11). This marked a significant increase over January 2006, when the rank was number 33, with Wikipedia receiving around 18.3 million unique visitors.[62] As of September 2019, Wikipedia has rank 9[9] among websites in terms of popularity according to Alexa Internet. In 2014, it received eight billion pageviews every month.[63] On February 9, 2014, The New York Times reported that Wikipedia has 18 billion page views and nearly 500 million unique visitors a month, "according to the ratings firm comScore."[19]

Wikipedia blackout protest against SOPA on January 18, 2012

On January 18, 2012, the English Wikipedia participated in a series of coordinated protests against two proposed laws in the United States Congress—the Stop Online Piracy Act (SOPA) and the PROTECT IP Act (PIPA)—by blacking out its pages for 24 hours.[64] More than 162 million people viewed the blackout explanation page that temporarily replaced Wikipedia content.[65][66]

Loveland and Reagle argue that, in process, Wikipedia follows a long tradition of historical encyclopedias that accumulated improvements piecemeal through "stigmergic accumulation".[67][68]

On January 20, 2014, Subodh Varma reporting for The Economic Times indicated that not only had Wikipedia's growth stalled, it "had lost nearly ten percent of its page views last year. There was a decline of about two billion between December 2012 and December 2013. Its most popular versions are leading the slide: page-views of the English Wikipedia declined by twelve percent, those of German version slid by 17 percent and the Japanese version lost nine percent."[69] Varma added that, "While Wikipedia's managers think that this could be due to errors in counting, other experts feel that Google's Knowledge Graphs project launched last year may be gobbling up Wikipedia users."[69] When contacted on this matter, Clay Shirky, associate professor at New York University and fellow at Harvard's Berkman Center for Internet & Society indicated that he suspected much of the page view decline was due to Knowledge Graphs, stating, "If you can get your question answered from the search page, you don't need to click [any further]."[69]

By the end of December 2016, Wikipedia was ranked fifth in the most popular websites globally.[70]

In January 2013, 274301 Wikipedia, an asteroid, was named after Wikipedia; in October 2014, Wikipedia was honored with the Wikipedia Monument; and, in July 2015, Wikipedia became available as 7,473 books for $500,000. In 2019, a species of flowering plant was named Viola wikipedia.[71]

In April 2019, an Israeli lunar lander, Beresheet, crash landed on the surface of the Moon carrying a copy of nearly all of the English Wikipedia engraved on thin nickel plates; experts say the plates likely survived the crash.[72][73]

In June 2019, scientists reported that all 16 GB of article text from the English Wikipedia have been encoded into synthetic DNA.[74]

Other Languages
Acèh: Wikipèdia
адыгабзэ: Википедие
Afrikaans: Wikipedia
Akan: Wikipedia
Alemannisch: Wikipedia
አማርኛ: ውክፔዲያ
Ænglisc: Wikipǣdia
Аҧсшәа: Авикипедиа
العربية: ويكيبيديا
aragonés: Biquipedia
ܐܪܡܝܐ: ܘܝܩܝܦܕܝܐ
armãneashti: Wikipedia
arpetan: Vouiquipèdia
অসমীয়া: ৱিকিপিডিয়া
asturianu: Wikipedia
Atikamekw: Wikipetcia
Avañe'ẽ: Vikipetã
Aymar aru: Wikipidiya
azərbaycanca: Vikipediya
تۆرکجه: ویکی‌پدیا
bamanankan: Wikipedi
Banjar: Wikipidia
Bân-lâm-gú: Wikipedia
Basa Banyumasan: Wikipedia
башҡортса: Википедия
беларуская: Вікіпедыя
беларуская (тарашкевіца)‎: Вікіпэдыя
भोजपुरी: विकिपीडिया
Bikol Central: Wikipedya
Bislama: Wikipedia
български: Уикипедия
Boarisch: Wikipedia
bosanski: Wikipedia
brezhoneg: Wikipedia
буряад: Википеэди
català: Viquipèdia
Чӑвашла: Википеди
Cebuano: Wikipedya
čeština: Wikipedie
Chamoru: Wikipedia
Chavacano de Zamboanga: Wikipedia
Chi-Chewa: Wikipedia
chiShona: Wikipidhiya
corsu: Wikipedia
Cymraeg: Wikipedia
dansk: Wikipedia
davvisámegiella: Wikipedia
Deitsch: Wikipedia
Deutsch: Wikipedia
ދިވެހިބަސް: ވިކިޕީޑިޔާ
dolnoserbski: Wikipedija
डोटेली: विकिपिडिया
eesti: Vikipeedia
Ελληνικά: Βικιπαίδεια
emiliàn e rumagnòl: Wikipedia
español: Wikipedia
Esperanto: Vikipedio
estremeñu: Wikipedia
euskara: Wikipedia
føroyskt: Wikipedia
français: Wikipédia
Frysk: Wikipedy
Fulfulde: Wikipeediya
furlan: Vichipedie
Gaeilge: Vicipéid
Gaelg: Wikipedia
Gagauz: Vikipediya
Gàidhlig: Uicipeid
galego: Wikipedia
ГӀалгӀай: Википеди
贛語: 維基百科
Gĩkũyũ: Wikipedia
گیلکی: ويکيپديا
ગુજરાતી: વિકિપીડિયા
गोंयची कोंकणी / Gõychi Konknni: Wikipidia
客家語/Hak-kâ-ngî: Wikipedia
хальмг: Бикипеди
한국어: 위키백과
Hausa: Wikipedia
Hawaiʻi: Wikipikia
հայերեն: Վիքիպեդիա
Արեւմտահայերէն: Ուիքիփետիա
हिन्दी: विकिपीडिया
hornjoserbsce: Wikipedija
hrvatski: Wikipedija
Bahasa Hulontalo: Wikipedia
Igbo: Wikipidia
Ilokano: Wikipedia
বিষ্ণুপ্রিয়া মণিপুরী: উইকিপিডিয়া
Bahasa Indonesia: Wikipedia
interlingua: Wikipedia
Interlingue: Wikipedia
ᐃᓄᒃᑎᑐᑦ/inuktitut: ᐅᐃᑭᐱᑎᐊ
Iñupiak: Uiqipitia
isiXhosa: Iwikipedia
isiZulu: Wikipedia
íslenska: Wikipedia
italiano: Wikipedia
עברית: ויקיפדיה
Kabɩyɛ: Wikipediya
kalaallisut: Wikipedia
Kapampangan: Wikipedia
къарачай-малкъар: Википедия
ქართული: ვიკიპედია
कॉशुर / کٲشُر: ویکیپیٖڈیا
kaszëbsczi: Wikipedijô
қазақша: Уикипедия
kernowek: Wikipedya
Kiswahili: Wikipedia
Kreyòl ayisyen: Wikipedya
kurdî: Wîkîpediya
Кыргызча: Уикипедия
кырык мары: Википеди
Ladino: Vikipedya
лакку: Википедия
لۊری شومالی: ڤیکیپدیا
latgaļu: Vikipedeja
Latina: Vicipaedia
latviešu: Vikipēdija
Lëtzebuergesch: Wikipedia
лезги: Википедия
lietuvių: Vikipedija
Ligure: Wikipedia
Limburgs: Wikipedia
lingála: Wikipedia
Lingua Franca Nova: Vicipedia
Livvinkarjala: Wikipedii
la .lojban.: du la .uikipedi'as.
Luganda: Wikipedia
lumbaart: Wikipedia
magyar: Wikipédia
मैथिली: विकिपिडिया
македонски: Википедија
Malagasy: Wikipedia
Malti: Wikipedija
Māori: Wikipedia
მარგალური: ვიკიპედია
مازِرونی: ویکی‌پدیا
Bahasa Melayu: Wikipedia
Minangkabau: Wikipedia
Mìng-dĕ̤ng-ngṳ̄: Wikipedia
Mirandés: Wikipedia
мокшень: Википедие
монгол: Википедиа
မြန်မာဘာသာ: ဝီကီပီးဒီးယား
Nāhuatl: Huiquipedia
Dorerin Naoero: Wikipediya
Na Vosa Vakaviti: Wikipedia
Nederlands: Wikipedia
Nedersaksies: Wikipedia
नेपाली: विकिपिडिया
नेपाल भाषा: विकिपिडिया
Napulitano: Wikipedia
нохчийн: Википеди
Nordfriisk: Wikipedia
Norfuk / Pitkern: Wikkapedya
norsk: Wikipedia
norsk nynorsk: Wikipedia
Nouormand: Viqùipédie
Novial: Wikipedie
occitan: Wikipèdia
олык марий: Википедий
Oshiwambo: Wikipedia
oʻzbekcha/ўзбекча: Vikipediya
ਪੰਜਾਬੀ: ਵਿਕੀਪੀਡੀਆ
Pälzisch: Wikipedia
Pangasinan: Wikipedia
پنجابی: وکیپیڈیا
Papiamentu: Wikipedia
Patois: Wikipidia
Перем Коми: Википедия
ភាសាខ្មែរ: វិគីភីឌា
Picard: Wikipédia
Piemontèis: Wikipedia
Tok Pisin: Wikipedia
Plattdüütsch: Wikipedia
polski: Wikipedia
Ποντιακά: Βικιπαίδεια
português: Wikipédia
Qafár af: Wikipedia
Qaraqalpaqsha: Wikipedia
qırımtatarca: Vikipediya
reo tahiti: Vitipetia
Ripoarisch: Wikipedia
română: Wikipedia
romani čhib: Vikipidiya
rumantsch: Vichipedia
Runa Simi: Wikipidiya
русиньскый: Вікіпедія
русский: Википедия
саха тыла: Бикипиэдьийэ
ᱥᱟᱱᱛᱟᱲᱤ: ᱣᱤᱠᱤᱯᱤᱰᱤᱭᱟ
Gagana Samoa: Wikipedia
संस्कृतम्: विकिपीडिया
sardu: Wikipedia
Scots: Wikipaedia
Seeltersk: Wikipedia
Sesotho sa Leboa: Wikipedia
Setswana: Wikipedia
shqip: Wikipedia
sicilianu: Wikipedia
Simple English: Wikipedia
SiSwati: Wikipedia
slovenčina: Wikipédia
slovenščina: Wikipedija
словѣньскъ / ⰔⰎⰑⰂⰡⰐⰠⰔⰍⰟ: Википєдїꙗ
ślůnski: Wikipedyjo
Soomaaliga: Wikipedia
کوردی: ویکیپیدیا
Sranantongo: Wikipedia
српски / srpski: Википедија
srpskohrvatski / српскохрватски: Wikipedia
ၽႃႇသႃႇတႆး : ဝီႇၶီႇၽီးတီးယႃး
Sunda: Wikipédia
suomi: Wikipedia
svenska: Wikipedia
Tagalog: Wikipedia
Taqbaylit: Wikipedia
tarandíne: Uicchipèdie
татарча/tatarça: Википедия
తెలుగు: వికీపీడియా
tetun: Wikipédia
ትግርኛ: ዊኪፔዲያ
тоҷикӣ: Википедия
Tsetsêhestâhese: Vekepete'a
Tshivenda: Wikipedia
Türkçe: Vikipedi
Türkmençe: Wikipediýa
тыва дыл: Википедия
удмурт: Википедия
ᨅᨔ ᨕᨘᨁᨗ: Wikipedia
українська: Вікіпедія
ئۇيغۇرچە / Uyghurche: ۋىكىپېدىيە
Vahcuengh: Veizgiek Bakgoh
vèneto: Wikipedia
vepsän kel’: Vikipedii
Tiếng Việt: Wikipedia
Volapük: Vükiped
walon: Wikipedia
文言: 維基大典
West-Vlams: Wikipedia
Winaray: Wikipedia
Wolof: Wikipedia
吴语: 维基百科
Xitsonga: Wikipediya
ייִדיש: וויקיפעדיע
Yorùbá: Wikipedia
粵語: 維基百科
Zazaki: Wikipediya
Zeêuws: Wikipedia
žemaitėška: Vikipedėjė
中文: 维基百科
kriyòl gwiyannen: Wikipédja
ဘာသာ မန်: ဝဳကဳပဳဒဳယာ
Sakizaya: u holic hananay