The Japanese Wikipedia (ウィキペディア日本語版, Wikipedia Nihongoban; lit. 'Japanese version of Wikipedia') is the Japanese edition of Wikipedia, a free, open-source online encyclopedia. Started on 11 May 2001, the edition attained the 200,000 article mark in April 2006 and the 500,000 article mark in June 2008. As of 27 May 2026, it has 1,503,384 articles with 25,612 active contributors, ranking sixth in the latter metric behind the English, Spanish, German, French and Italian.