Wales is an atheist. In an interview with Big Think, he said his philosophy is firmly rooted in reason, and that he is a complete non-believer. Wales has lived in London, England since 2012.

In January 2001, Wikipedia began as a side-project of Nupedia, to allow collaboration on articles prior to entering the peer-review process. The name was suggested by Sanger on 11 January 2001 as a portmanteau of the words wiki (Hawaiian for "quick") and encyclopedia.

Encyclopædia Britannica also argued that a breakdown of the errors indicated that the mistakes in Wikipedia were more often the inclusion of incorrect facts, while the mistakes in Britannica were "errors of omission", making "Britannica far more accurate than Wikipedia, according to the figures".

Yet, the quality of Wikipedia articles is very high [3]. This is true even in many specialized topics, such as anatomy, biology, or medicine, where Wikipedia is as accurate as the professional sources [4–6], even though sometimes it does not score high on readability.