There are a lot of encyclopedia sites in which you will have full access to encyclopedias online. Wikipedia is one among that which you all guys know of (Wikipedia).
A list of encyclopedias by Wikipedia – https://en.wikipedia.org/wiki/List_of_online_encyclopedias
A few are provided below :-
The online version of the Encyclopedia Britannica is a trusted source used by more than 4,755 universities worldwide, including Yale, Harvard and Oxford. The site includes access to all 32 volumes of the Encyclopedia Britannica, a dictionary, a thesaurus, newspaper and magazine articles and a world atlas. You’ll have to work fast though. You can only use this source for free for seven days. After that, you’ll need to pay $69.95 a year for full access.
Encyclopedia.com is a free online encyclopedia that allows you to search more than 57,000 articles from the Columbia Encyclopedia. Each article contains links to images, as well as magazine and newspaper pieces. Encyclopedia.com also includes other reference works, such as the Oxford Dictionaries and the Britannica Concise Encyclopedia.
Bartleby.com has a great collection of free reference materials, books and verse. Searchable encyclopedias include the Columbia Encyclopedia, the Columbia Gazetteer of North America, the Encyclopedia of World History and the World Fact Book.
Pearson Education’s Infoplease provides free access to more than 57,000 articles from the Columbia Encyclopedia (Sixth Edition.) Other references, such as an almanac, dictionaries and a thesaurus make this site a good all around tool for research papers.
The free encyclopedia from Questia includes more than 52,000 entries from the Columbia Encyclopedia (Sixth Edition.) There are also loads of supplemental goodies in the reference library, such as full-text books and articles from journals, magazines and newspapers.
Select from nine subject areas, including science and technology, space, and history, type in a keyword, and let dkonline.encyclopedia link you to websites providing the information you need. Sites could utilize videos, virtual tours, timelines and more. You can also download and print free images.
Encyclopedia of Life is a relatively new Internet venture. Launched in May of 2007, the site aims to document all species of life on Earth. The collaborative and constantly updated encyclopedia is free for everyone to use and perfect for students who are writing research papers on science or biology.
The Scholarpedia site is similar in format to Wikipedia, but it is a much better free resource for research papers. All of the entries have been written and approved by an actual scholar, which means you won’t have a problem when it comes time to cite sources. Featured encyclopedias cover topics like computational neuroscience, dynamical systems, computational intelligence and astrophysics.
Wikipedia is one of the most popular sites in the world, but it is not without problems. Anybody can write and edit Wikipedia entries. This means that you can’t always count on the site for factual information. You also can’t cite Wikipedia as a source for most student research papers. Nevertheless, Wikipedia is worth visiting because it is free and it can lead you to more valuable and reliable sources of information.
Citizendium is a wiki that seems to be a compromise between the free-for-all that is Wikipedia and the strict supervision that accompanies Scholarpedia. One of Wikipedia’s founders, Larry Sanger, created Citizendium in the hopes of improving on Wikipedia’s model. With what the site refers to as “gentle oversight”, all articles are subject to approval by the site’s editorial team. Articles that haven’t been approved will have an accompanying disclaimer, which helps to prevent people from taking potentially false information to heart. Also, you must register under your real name to become a contributor, unlike Wikipedia. Although the site is still in beta form, it is quickly becoming a popular alternative to Wikipedia, one that Sanger feels will “probably succeed“.
MSN Encarta is another online encyclopedia that bypasses the problems that plague Wikipedia. All entries have been written and fact-checked by professionals and the site will never be vandalized. However, like Encyclopedia Britannica Online, this site requires a subscription fee. For $29.95 a year, you can access MSN Encarta in its entirety, including the site’s accompanying thesaurus, world atlas and other research tools for students.
Conservapedia is a conservative, Christian-influenced wiki encyclopedia that was created as a response to Wikipedia’s alleged left-wing bias. The information found on this site is free of foul language, sexual topics and anything else deemed offensive by the site’s editorial staff. If you feel that Wikipedia shows a strong bias toward liberal views, then this site may suit your needs. All Conservapedia users are asked to follow the site’s seven Commandments.
Uncyclopedia is an ambitious spoof of Wikipedia. It could be seen as an over-the-top response to Wikipedia users, also known as “Wikipedians”, who seem to take the site much too seriously. From the home page’s logo to the formatting of each entry, the parallels between the two sites are uncanny and well-executed. Make no mistake, however. Nothing on Uncyclopedia should be taken as fact, which may be another dig at Wikipedia’s occasional inaccuracy. If you are fed up with Wikipedia’s many faults and want to have a good laugh, check out this satirical site.