| Website | Founded | Closed | Description/focus | Languages available | Copyrighting of user contributions | Registration required? | Price |
|---|
| Answers.com | 2005}} | - | All topics | English | Yes |
| Askbot | 2009}} | N/A | varies | varies | varies |
| Ask.fm | 2010}} | - | Social topics | 49 languages | Yes |
| Ask Me Help Desk | 2003}} | - | Many topics | English and a few others | Yes | Free |
| Ask MetaFilter | 2003}} | - | Music | English | All posts are copyright to their original authors.[1] | No to browse, yes to contribute |
| Avvo | 2006}} | - | Legal | English | Yes |
| Baidu Knows | 2005}} | - | Many topics | Chinese | No to browse, yes to contribute |
| BlikBook | 2010}} | N/A | Local academic | English | Yes |
| Blurtit | 2006}} | - | All topics | English | Yes |
| Brainly | 2009}} | - | Academic | 12 languages | Contributed content owned by its author(s) | No to browse, yes to contribute |
| Brilliant.org | 2013}} | - | Science, technology, math | English | User retains ownership; Brilliant can use, distribute, modify.[2] | Yes/Paid[3] | ₹23,900 for life time use |
| ChaCha | 2006}} | 2016}} | Many topics | English | Owned by ChaCha.[4] | na |
| Chegg | 2005}} | - | Academic | English | Owned by Chegg Inc.[5] | Yes / paid |
| eNotes | 2005}} | - | Academic | English | Owned by eNotes.com[6] | Yes / paid | 14.99/month |
| Experience Project | 2007}} | 2016 | Social topics | English | Terms of use for Experience Project[7] | anonymous |
| Experts-Exchange | 1996}} | - | Information technology | Yes / paid |
| Fixya | 2005}} | - | Consumer products | English | Yes |
| GirlsAskGuys | 2007}} | - | Social topics | English | Yes |
| Google Answers | 2002}} | 2006}} | English | Yes |
| Google Questions and Answers | 2007}} | 2014}} | Many topics | Russian, Chinese, English, French | na |
| Gutefrage.net | 2006}} | - | German | Yes | Free |
| HealthTap | 2011}} | - | Health information | English | No |
| Internet Oracle | 1989}} | - | All topics (humorous) | English | No |
| Jelly | 2013}} | 2017}} | All topics | English |
| Jobstr | 2011}} | - | Business | English |
| Knowledge Search | 2002}} | - | Many topics | Korean |
| LinkedIn Answers | 2007}} | 2013}} | Business | Yes |
| MadSci Network | 1995}} | - | Science | English |
| Mahalo.com | 2007}} | 2014}} | Many topics | English | na |
| Ответы@Mail.Ru | 2006}} | - | Russian |
| ProfNet | 1992}} | - | Journalists | English | Yes |
| Quora | 2009}} | - | Many topics | 9 languages | Contributions owned by the author. Quora granted "worldwide, non-exclusive, royalty-free license" to content use, distribution, or modification.[8] | Yes, except to view single answers |
| r/AskHistorians | 2012}} | - | History | English | No to browse, yes to contribute |
| Sharecare | 2009}} | - | Health and wellness | English | No |
| Spring.me (formerly Formspring) | 2009}} | 2015}} | All topics | English | Yes |
| Stack Exchange | 2008}} | - | Many topics | English (Q&A about other languages takes place in those langugaes as well as English) | Contributions owned by the author. Contributions "perpetually and irrevocably licensed to Stack Exchange under the Creative Commons Attribution Share Alike license".[9] | No to browse and ask/answer, yes to contribute fully |
| Stack Overflow | 2008}} | - | Software development | English, Spanish, Russian, Portuguese, and Japanese | No to browse and ask/answer, yes to contribute fully |
| The Straight Dope | 1973}} (print) | - | Many topics | English | No |
| Transtutors | 2007}} | - | Academic | English | Owned and operated by Transweb Educational Services[10] | Yes / paid |
| English Wikipedia Reference Desk | 2004}} | - | Many topics | English | CC-BY-SA 3.0 and GFDL dual license | No |
| Yahoo! Answers | 2005}} | - | All topics | 13 languages | Contributions owned by the author. Yahoo retains rights to the use, distribution or modification.[11] | No |
| Zhihu | 2011}} | - | Many topics | Chinese and a few others | Owned and operated by the original authors. | No |
| WikiAnswers | 2002}} | 2018 | Many topics | Subsumed by Answers.com (one of several concurrent URLs) |
| Whiz Answers | 2018}} | - | All topics about Nigeria | English | Contributions owned by the author. Whiz retains rights to the use, distribution or modification.[12] | Yes |
| TXN (The Experts Network) | 2011}} | ? | Sports | English | No |
| Uclue | 2007}} | 2017}} | Many topics | English | Yes |
| 3form | 1998}} | 2016}} | Many topics | English | na | na |
|
1. ^{{cite web|url=http://faq.metafilter.com/#237 |title=FAQ: Who owns the copyright on MetaFilter content? |last=Haughey |first=Matt |work=MetaFilter |accessdate=20 May 2014}}
2. ^{{cite web|url=https://brilliant.org/terms-of-use/ |title=Terms of use of Brilliant.org |work=Brilliant.org |accessdate=8 October 2014}}
3. ^https://brilliant.org/premium/?elementId=clicked_b2_mobile_header
4. ^{{cite web|url=http://about.chacha.com/terms-of-use/ |title=Terms of use of the ChaCha service |work=ChaCha.com |accessdate=3 January 2016}}
5. ^{{cite web|url=https://www.chegg.com/termsofuse |title=Terms of use of Chegg.com |work=Chegg |accessdate=3 January 2016}}
6. ^{{cite web|url=http://www.enotes.com/help/tos |title=Terms of use of eNotes.com |work=eNotes |accessdate=3 January 2016}}
7. ^{{cite web|url=http://www.experienceproject.com/terms.php |title=Statement of Rights and Responsibilities |work=Experience Project |accessdate=5 August 2015}}
8. ^{{cite web|url=https://www.quora.com/about/tos |title=Terms of use of the Quora service |work=Quora |accessdate=3 January 2016}}
9. ^{{cite web|url=http://stackexchange.com/legal/terms-of-service |title=Terms of Service - Stack Exchange |work=Stack Exchange |accessdate=3 January 2016}}
10. ^{{cite web|url=http://www.transtutors.com/terms-conditions.aspx |title=Terms & Conditions of Transtutors.com |work=Transtutors |accessdate=9 January 2014}}
11. ^{{cite web|url=https://policies.yahoo.com/us/en/yahoo/terms/utos/index.htm |title=Terms of use of the Yahoo Answer service |work=Yahoo |accessdate=3 January 2016}}
12. ^{{cite web|url=https://whiz.com.ng/information/terms_and_conditions |title=Terms and Conditions of Whiz Question and Answer |work=Whiz |accessdate=15 December 2018}}
{{DEFAULTSORT:Comparison of QandA sites}}