He graduated from high school in 1986 and went off to Reed College, majoring in philosophy. In college he became interested in the Internet and its publishing abilities. He set up a listserver as a medium for students and tutors to meet up for "expert tutoring" and "to act as a forum for discussion of tutorials, tutorial methods, and the possibility and merits of a voluntary, free network of individual tutors and students finding each other via the Internet for education outside the traditional university setting." He started and moderated a philosophy discussion list, the Association for Systematic Philosophy. Sanger wrote in 1994 a manifesto for the discussion group: "The history of philosophy is full of disagreement and confusion. One reaction by Philosophers to this state of things is to doubt whether the truth about philosophy can ever be known, or whether there is any such thing as the truth about philosophy. But there is another reaction: one may set out to think more carefully and methodically than one's intellectual forebears."
Sanger received a Bachelor of Arts degree in philosophy from Reed College in 1991, a Master of Arts from Ohio State University in 1995, and a Doctor of Philosophy from Ohio State University in 2000. Beginning in 1998 he ran a website called "Sanger's Review of Y2K News Reports", a resource for those concerned about the year 2000 Problem, such as managers of computer systems.
It was Jimmy Wales, along with other people, who came up with the broader idea of an open-source, collaborative encyclopedia that would accept contributions from ordinary people and it was Wales who invested in it. Sanger came up with the name "Wikipedia", which he later said was "a silly name for what was at first a very silly project". Sanger first conceived of the wiki-based encyclopedia project only as a means to hopefully accelerate Nupedia's slow growth. During Wikipedia's critical first year of growth, Sanger spearheaded and guided the following that gathered around this nucleus. Through this early period, he served as Wikipedia's "chief organizer", a position which has not been filled since his departure from Wikipedia. Sanger is also credited with creating and enforcing many of the policies and strategy that made Wikipedia possible during its first formative year. By May 2001 there were 3,900 articles. By the end of the year in 2001, the site had about 15,000 articles and upwards of 350 Wikipedians.
Since Sanger parted ways with Wikipedia in 2002, he has been critical of its accuracy, among other things. In December 2004, Sanger wrote a critical article for the website Kuro5hin, in which he stated that Wikipedia is not perceived as credible among librarians, teachers, and academics when it does not have a formal review process and it is "anti-elitist". In September 2009, Sanger mentioned one reason for distancing himself from Wikipedia: "I thought that the project would never have the amount of credibility it could have if it were not somehow more open and welcoming to experts." He pointed out, "The other Problem was the community had essentially been taken over by trolls to a great extent. That was a real Problem, and Jimmy Wales absolutely refused to do anything about it." Wales responded by stating, "I think very highly of Larry Sanger, and think that it is unfortunate that this silly debate has tended to overshadow his work."
In December 2005, Digital Universe Foundation announced that Sanger had been hired as Director of Distributed Content Programs. He would be a key organizer of the Digital Universe Encyclopedia web projects which was launched in early 2006. The Digital Universe encyclopedia has recruited recognized experts to write articles, and to check user-submitted articles for accuracy. The first step in this effort was the expert-authored and edited Encyclopedia of Earth, an electronic reference about the Earth.
The question of accuracy over Wikipedia article content spurred Sanger to unveil plans for a new encyclopedia called Citizendium, short for "citizens' compendium". At the Wizards of OS conference in September 2006, Sanger announced Citizendium as a fork of Wikipedia. The objectives of the fork were to address various perceived flaws in the Wikipedia system. The main differences would be no anonymous editing: every author/editor would have to be identified by his/her real name, no "top-down" hierarchy of editors: it would aspire to be a "real encyclopedia."
On March 25, 2007, Citizendium officially launched. In early 2007, Sanger announced he would not head Citizendium indefinitely. Two weeks after the launch of Citizendium, Sanger criticized Wikipedia, stating the latter was "broken beyond repair," and had a range of problems "from serious management problems, to an often dysfunctional community, to frequently unreliable content, and to a whole series of scandals." Citizendium was an effort by Sanger to establish a scholarly and credible online encyclopedia which aimed to bring more accountability and academic quality to articles.
He has worked at the WatchKnowLearn project, a non-profit organization which focuses on educating young children using educational videos and other media on the web. Sanger was the executive Director of the system. It is a non-profit funded by grants, Philanthropists, and the Community Foundation of North West Mississippi. Sanger headed the development of WatchKnowLearn from 2008 to 2010. It consists of a repository of educational videos for kindergarten to the 12th grade. In February 2013, it ranked as the No. 1 search result among educational videos on Google's search engine, with page views surmounting 6 million each month. In 2010 and 2011, he continued working on developing a web-based reading-tutorial application for beginning readers which was launched as Reading Bear in 2012. It uses the principles of phonics, using multimedia presentations such as videos, PowerPoint presentations, and ebooks. In addition to aiming to teach children to pronounce words, it aims to teach the meaning and context of each word.
In early 2009, Sanger effectively ceased to edit Citizendium, although an announcement confirming this was not made until July 30, 2009, on the Citizendium-l mailinglist. On September 22, 2010, Sanger stepped down as editor-in-chief of Citizendium but said, at the time, that he would continue to support the project.
In April 2010 Sanger sent a letter to the FBI detailing his concern that Wikimedia Commons was hosting child pornography in its pedophilia and lolicon categories later clarified as "obscene visual representations of the abuse of children". Sanger said that he felt it was his "civic duty" to report the images. Sanger told FoxNews.com that, in 2012, he worked with NetSpark to get them to donate or heavily discount its pornographic image filtering Technology for use by Wikipedia. NetSpark attempted to contact the Wikimedia Foundation in July/August 2012, but received no response at that time. In December 2010 Sanger said he considered WikiLeaks "enemies of the U.S. — not just the government, but the people."
Ars Technica reporter Timothy B. Lee said in 2011 that Citizendium was "dead in the water". Lee noted that Citizendium's late start was a disadvantage, and that Citizendium's growth was also hindered by an "unwieldy editing model". In 2014, the number of Citizendium contributors was fewer than 100, and the number of edits per day was about "a dozen or so", according to Winthrop University's Dean of Library Services. Citizendium has about 17,000 articles, of which 160 have been expert reviewed as of August 2016.
In February 2013, Sanger announced a project he named Infobitt - a crowdsourced news portal. On Twitter, he wrote: "My new project will show the world how to crowdsource high-quality content—a Problem I've long wanted to solve. Not a wiki". The site, which sought to be a crowdsourced news aggregator, went online in December 2014. In July 2015, Sanger announced that the project had run out of money, he had let the programmers go, he was himself looking for a job, and that it was impossible to do a full launch of the project as the code behind it was still only capable of working "at a small scale". The site is no longer active.
In 2015, Sanger was interviewed by Zach Schwartz in Vice. In the interview, he said, among other things, that "I think Wikipedia never solved the Problem of how to organize itself in a way that didn't lead to mob rule" and that since he left the project, "People that I would say are trolls sort of took over. The inmates started running the asylum."
Sanger told Inverse in December 2017 that Everipedia is "going to change the world in a dramatic way, more than Wikipedia did." Sanger said, "Everipedia is the encyclopedia of everything, where topics are unrestricted, unlike on Wikipedia." It is an open encyclopedia contributed by many different editors that will use blockchain Technology.