| Site | Language | Description | Access |
|---|
| Archimedes-lab.org | English | Edutainment | Free |
| Baidu Baike | Chinese | Collaborative online encyclopedia hosted by the major Chinese search engine Baidu | Free |
| Banglapedia | Bangla, English | General interest | Free |
| The Canadian Encyclopedia | English, French | General Interest (original content of the hard copy Canadian Encyclopedia) | Free |
| Chinese Encyclopedia | Chinese | General interest | Free |
| Citizendium | English | Wiki-based free encyclopedia project spearheaded by Larry Sanger, co-founder of Wikipedia | Free |
| Columbia Encyclopedia | English | General interest | Free |
| Compton's Encyclopedia | English | General interest | Free |
| Conservapedia | English | Semi-open wiki written from politically right-wing and Biblical literalist perspectives. | Free |
| Credo Reference | English | General interest and subject-specific encyclopedias | Subscription |
| Crnogorska Enciklopedija | Montenegrin | General interest (hopes to encourage a Montenegrin language Wikipedia) | Free |
| Den Store Danske Encyklopædi | Danish | General interest | Free |
| Deu Sözlük | Turkish | General interest | Free |
| Digital Universe | English | Collection of articles on educational, cultural, and scientific topics | Free |
| Diplopedia | English | US State Department internal encyclopedic wiki, available for diplomats and overseas US agents to use | Access only through the State Department |
| Doosan Encyclopedia | Korean | General | Free |
| Ekşi Sözlük | Turkish | General interest | Free |
| Encarta | English | General interest | Defunct |
| Encyclopædia Britannica | English | General interest | Limited free access and features, subscription for full access |
| Encyclopædia Britannica –1911 Edition | English | General interest | Public domain: completely free access from several online sources |
| Encyclopedia of China | Chinese | General interest | Subscription |
| Encyklopedia Internautica | Polish | General interest | Free |
| Enciclopedia Libre | Spanish | Fork of the Spanish Wikipedia, using wiki software, released under the GFDL | Free |
| Enciclopedia României | Romanian | Collaborative encyclopedia about Romania. | Free |
| Encyclopædia Universalis | French | General interest encyclopedia published by Encyclopedia Britanica | Subscription |
| Everything2 | English | General interest, users can submit articles on the topic of essentially anything | Free |
| FAQ | English | A collection of searchable FAQs | Free |
| Gale Virtual Reference Library | English | Database for search of source material of an academic nature | Subscription |
| GNUPedia | English | General interest articles are released under a GNU license | Free |
| Grand Larousse encyclopédique | French | General interest | Free |
| Grolier Multimedia Encyclopedia | English | Targeted at the younger researcher, it contains the text of the American Academic Encyclopedia | Subscription |
| Holocaust Encyclopedia | English, Arabic, Farsi, French, Spanish | Holocaust related articles | Free |
| Hudong | Chinese | General interest. China's largest wiki | Free |
| Hutchinson Encyclopedia | English | General interest | Free |
| Infoplease | English | General interest | Free |
| Internetowa encyklopedia PWN | Polish | General interest | Free |
| Interpedia | English | General interest, the first site to propose a free encyclopedia written by users. Now defunct. | No longer exists |
| Kalb Encyclopedia | Esperanto | General interest. The first online Esperanto encyclopedia | Free |
| Kdo byl kdo | Czech | Biographies on notable Czech and Slovak people | Free |
| Keyinpedia | Chinese | General interest | Free |
| Knol | English | General interest | Free |
| Kussmaul Encyclopedia | English | General interest with emphasis on science and the arts. First commercial online encyclopedia (1981-93). | Subscription |
| Marefa | Arabic | General interest | Free |
| Meyers Konversations-Lexikon 4. ed. 1888 - 1892 | German | General interest | Free |
| Nationalencyklopedin | Swedish | General interest, the most comprehensive contemporary Swedish language encyclopedia | Subscription |
| New World Encyclopedia | English | General interest | Free |
| Nupedia | English | Combined with GNUpedia | Free |
| Open Site | English | Categorized community-built encyclopedia, inspired by the Open Directory Project | Free |
| Private Sözlük | Turkish | Collaborative hypertext Turkish dictionary and encyclopedia site that shares a similar concept with Everything2 or H2G2 | Free |
| Probert Encyclopaedia | English | General interest | Free |
| Quid | French | General interest | Free |
| Scholarpedia | English | Articles are written by scholars and peer-reviewed for accuracy | Free |
| Store norske leksikon | Norwegian (Bokmål) | General interest | Free |
| Susning.nu | Swedish | A Swedish language wiki | Free |
| Từ điển Bách khoa toàn thư Việt Nam | Vietnamese | General interest. State-sponsored encyclopedia. | Free |
| Veropedia | English, Dutch, Spanish | Mirrors stable versions of selected English Wikipedia articles | Free |
| Vikidia | French, Spanish | Articles designed for children ages 8-13 | Free |
| WIEM Encyklopedia | Polish | General interest | Free |
| Wikipedia | See list here | Wiki-based free general interest encyclopedia | Free, Copyleft |
| WikiPilipinas | English | Based on the Wikipedia model, from the Philippines point-of-view | Free |
| World Book Encyclopedia | English | General interest | Subscription |
| Site | Language | Description | Access |
|---|
| Battlestar Wiki | English, Simple English, German, Spanish, Turkish, Malay, French, Chinese | Battlestar Galactica-related articles | Free |
| Don Markstein's Toonopedia | English | Focuses on articles pertaining to print and animated cartoons | Free |
| H2G2 | English | Collection of sometimes humorous encyclopedia articles, based on Douglas Adams's The Hitchhiker's Guide to the Galaxy. | Free |
| Heroes Wiki | English, Dutch, French, German, Hebrew, Italian, Portuguese, Spanish, Swedish, Turkish | Contains articles pertaining to the American television drama Heroes. | Free |
| Lambiek | English, Dutch | Articles on comic strips and comic artists | Free |
| Lostpedia | English, German, Spanish, French, Italian, Japanese, Dutch, Polish, Portuguese, Russian, Chinese | Contains articles pertaining to the hit drama Lost | Free |
| Memory Alpha | English, Bulgarian, Chinese, Czech, Dutch, Esperanto, French, German, Polish, Portuguese, Russian, Serbian, Spanish and Swedish | Articles about Star Trek | Free |
| Project Galactic Guide | English | Inspired by The Hitchhiker's Guide to the Galaxy | Free |
| The Rocklopedia Fakebandica | English | Articles on fake bands from popular entertainment | Free |
| TvTropes | English, German, Esperanto, Spanish, Frrench, Norsk, Suomi, Svenska, Al Bhed, Quenya | Articles related to the devices and conventions that a fiction writer can reasonably rely on as being present in the audience members' minds and expectations | Free |
| Wookieepedia | English, German, Spanish, Bulgarian, Danish, Finnish, French, Croatian, Hungarian, Italian, Japanese, Dutch, Norwegian, Polish, Portuguese, Russian, Romanian, Slovak, Slovene, Swedish, Chinese | Star Wars related articles | Free |
| WoWWiki | English, German, Spanish, French, Czech, Danish, Greek, Persian, Finnish, Hebrew, Hungarian, Icelandic, Italian, Lithuanian, Latvian, Dutch, Nynorsk, Bokmål, Polish, Portuguese, Brazilian Portuguese, Russian, Slovak, Korean, Japanese, Chinese | World of Warcraft related articles | Free |
| Site | Language | Description | Access |
|---|
| Cut-the-knot | English | Mathematics related topics | Free |
| Encyclopaedia of Mathematics | English | Encompasses articles on the topic of mathematics | Free |
| EqWorld | English, Russian, German, French, Italian, Spanish | Articles on mathematical equations | Free |
| MathWorld | English | Articles on a wide variety of math related topics | Free |
| On-Line Encyclopedia of Integer Sequences | English | Encyclopedia of number sequences (what is next term after 1,2,4,9,20,48,115, ..., say?) | Free |
| PlanetMath | English | Math related topics and articles | Free/GNU |
| The QED Project | English | A project to establish a "distributed, computerized repository that rigorously represents all important, established mathematical knowledge." | Free |
| Site | Language | Description | Access |
|---|
| Animal Diversity Web | English | Student wiki-type database at the University of Michigan of animal natural history, distribution, classification, and conservation biology. | Free |
| ARKive | English | Visual and audio recordings of the world's species | Free |
| Encyclopedia of Life | English, French | Seeks to categorize all 1.8 million known species on the planet | Free |
| Encyclopedia of Life Sciences | English | Biology related articles | Subscription |
| Encyclopedia of Life Support Systems | English | Articles about the natural and social sciences | Subscription |
| Erowid | English | Information about psychoactives substances | Free |
| FishBase | English, Spanish, Portuguese, French, German, Italian, Dutch, Chinese (Simplified Han), Chinese (Traditional Han), Bahasa Malay, Indonesian, Greek, Swedish, Russian, Farsi, Vietnamese, Thai, Lao, Hindi, Bangla | Articles on fish species | Free |
| Flora Europaea | English | Covers different plant species | Free |
| Macroscopic Observatory | English | Covers Flora and Fauna | Free |
| MicrobeWiki | English | Covers microbes | Free |
| Palaeos | English | Covers palaeontology | Free |
| Wikispecies | English | Seeks to create a catalogue of all living things | Free |
A list of 69 online medical wiki encyclopedias has been created by David Rothman.[2]