Wikipedia Launched
Jimmy Wales and Larry Sanger launched Wikipedia as a free online encyclopedia
January 15, 2001
The Free Encyclopedia Anyone Can Edit
On January 15, 2001, Jimmy Wales and Larry Sanger launched Wikipedia — a free online encyclopedia that anyone could write and edit. The idea seemed absurd. How could an encyclopedia written by anonymous volunteers be accurate or reliable? Within a year it had 20,000 articles in 18 languages. Within a decade it had 20 million articles in 280 languages. Today it is the fifth most visited website on Earth and the largest repository of human knowledge ever assembled.
How It Actually Works
Wikipedia runs on the assumption that more eyes mean fewer errors — that a community of editors policing each other's contributions will converge on accuracy over time. The system is imperfect: articles on obscure topics can go years with mistakes; famous people are sometimes vandalized. But on most major topics, Wikipedia's accuracy has been found to rival printed encyclopedias. It is maintained by roughly 60,000 active volunteers and operated by the non-profit Wikimedia Foundation on a budget a fraction of other major websites.
What It Replaced
Encyclopaedia Britannica — which had been published continuously since 1768 — stopped printing its physical edition in 2012, citing Wikipedia as a primary reason. Microsoft's Encarta, once the standard digital reference, shut down in 2009. Wikipedia made encyclopedic knowledge free and searchable in seconds. It is also the source that trained many large AI language models. The idea that a free, collaboratively written reference work could replace centuries of commercial publishing once seemed impossible.