Stack Overflow

website for professional and enthusiast programmers

Encyclopedia from Wikipedia, the free encyclopedia

Stack Exchange, Inc.
Stack Overflow logo.svg Top Questions Page Screenshot.png
Screenshot in June 2022
Type of site
Knowledge market
Question and answer
Available inEnglish, Spanish, Russian, Portuguese, and Japanese
Created byJeff Atwood and Joel Spolsky
CEOPrashanth Chandrasekar Edit this at Wikidata
Launched15 September 2008; 14 years ago (2008-09-15)[1]
Content license
  • CC BY-SA 2.5 (until April 2011)
  • CC BY-SA 3.0 (until May 2018)
  • CC BY-SA 4.0
Written inC#[3]

Stack Overflow is a question and answer website for professional and enthusiast programmers. It is the flagship site of the Stack Exchange Network.[4][5][6] It was created in 2008 by Jeff Atwood and Joel Spolsky.[7][8] It features questions and answers on a wide range of topics in computer programming.[9][10][11] It was created to be a more open alternative to earlier question and answer websites such as Experts-Exchange. Stack Overflow was sold to Prosus, a Netherlands-based consumer internet conglomerate, on 2 June 2021 for $1.8 billion.[12]

The website serves as a platform for users to ask and answer questions, and, through membership and active participation, to vote questions and answers up or down similar to Reddit and edit questions and answers in a fashion similar to a wiki.[13] Users of Stack Overflow can earn reputation points and "badges"; for example, a person is awarded 10 reputation points for receiving an "up" vote on a question or an answer to a question,[14] and can receive badges for their valued contributions,[15] which represents a gamification of the traditional Q&A website. Users unlock new privileges with an increase in reputation like the ability to vote, comment, and even edit other people's posts.[16]

As of March 2021 Stack Overflow has over 14 million registered users,[17] and has received over 21 million questions and 31 million answers.[18] The site and similar programming question and answer sites have globally mostly replaced programming books for day-to-day programming reference in the 2000s, and today are an important part of computer programming.[19] Based on the type of tags assigned to questions, the top eight most discussed topics on the site are: JavaScript, Java, C#, PHP, Android, Python, jQuery, and HTML.[20]


The website was created by Jeff Atwood and Joel Spolsky in 2008.[7] The name for the website was chosen by voting in April 2008 by readers of Coding Horror, Atwood's popular programming blog.[21] On 31 July 2008, Jeff Atwood sent out invitations encouraging his subscribers to take part in the private beta of the new website, limiting its use to those willing to test out the new software. On 15 September 2008 it was announced that the public beta version was in session and that the general public was now able to use it to seek assistance on programming related issues. The design of the Stack Overflow logo was decided by a voting process.[22]

On 3 May 2010, it was announced that Stack Overflow had raised $6 million in venture capital from a group of investors led by Union Square Ventures.[23]

In 2019, Stack Overflow named Prashanth Chandrasekar as its chief executive officer and Teresa Dietrich as its chief product officer.[24]

In June 2021, Prosus, a Netherlands-based subsidiary of South African media company Naspers, announced a deal to acquire Stack Overflow for $1.8 billion.[25]

Security breach

In early May 2019, an update was deployed to Stack Overflow's development version. It contained a bug which allowed an attacker to grant themselves privileges in accessing the production version of the site. Stack Overflow published on their blog that approximately 184 public network users were affected by this breach, which "could have returned IP address, names, or emails".[26][27]


Stack Overflow only accepts questions about programming that are tightly focused on a specific problem. Questions of a broader nature—or those inviting answers that are inherently a matter of opinion—are usually rejected by the site's users, and marked as closed. The sister site is intended to be a venue for broader queries, e.g. general questions about software development.[28]

Closing questions is a main differentiation from other Q&A sites like Yahoo! Answers and a way to prevent low quality questions.[29] The mechanism was overhauled in 2013; questions edited after being put "on hold" now appear in a review queue.[30] Jeff Atwood stated in 2010 that duplicate questions are not seen as a problem but rather they constitute an advantage if such additional questions drive extra traffic to the site by multiplying relevant keyword hits in search engines.[31]

All user-generated content is licensed under Creative Commons Attribute-ShareAlike license, version 2.5, 3.0, or 4.0 depending on the date the content was contributed.[2][32]


Top Stack Overflow tags

A 2013 study has found that 75% of users only ask one question, 65% only answer one question, and only 8% of users answer more than 5 questions.[33] To empower a wider group of users to ask questions and then answer, Stack Overflow created a mentorship program resulting in users having a 50% increase in score on average.[34] As of 2011, 92% of the questions were answered, in a median time of 11 minutes.[35] Since 2013, the Stack Exchange network software automatically deletes closed questions that meet certain criteria, including having no answers in a certain amount of time.[36]

As of August 2012, 443,000 of the 1.3 million registered users had answered at least one question, and of those, approximately 6,000 (0.46% of the total user count) had earned a reputation score greater than 5000.[37] Reputation can be gained fastest by answering questions related to tags with lower expertise density, doing so promptly (in particular being the first one to answer a question), being active during off-peak hours, and contributing to diverse areas.[37]

In 2016, 1.5 million posts were deleted, of which about 8% were deleted by moderators.[38]


Stack Overflow is written in C#[3] using the ASP.NET MVC (Model–View–Controller) framework, and Microsoft SQL Server for the database[39] and the Dapper object-relational mapper used for data access.[40] Unregistered users have access to most of the site's functionality, while users who sign in can gain access to more functionality, such as asking or answering a question, establishing a profile and being able to earn reputation to allow functionality like editing questions and answers without peer review or voting to close a question.[41]


Stack Overflow won the 2020 Webby People's Voice Award for Community in the category Web.[42]

The site's culture has been criticized for being unfriendly, especially in the context of gender differences in participation.[43]

A study from the University of Maryland found that Android developers that used only Stack Overflow as their programming resource tended to write less secure code than those who used only the official Android developer documentation from Google, while developers using only the official Android documentation tended to write significantly less functional code than those who used only Stack Overflow.[44]

See also


  1. ^ Spolsky, Joel (15 September 2008). "Stack Overflow Launches". Joel on Software. Archived from the original on 14 February 2021. Retrieved 7 July 2014.
  2. ^ a b "Creative Commons Licensing UI and Data Updates". Archived from the original on 23 May 2020. Retrieved 26 May 2020.
  3. ^ a b "Which tools and technologies are used to build the Stack Exchange Network?". Meta Stack Overflow. Stack Overflow. Archived from the original on 20 March 2017. Retrieved 19 March 2017.
  4. ^ Sewak, M.; et al. (18 May 2010). "Finding a Growth Business Model at Stack Overflow, Inc" (PDF). Stanford CasePublisher. Stanford University School of Engineering. Rev. 20 July 2010 (2010–204–1). 204-2010-1. Archived (PDF) from the original on 13 August 2012. Retrieved 23 May 2014.
  5. ^ a b Jeff Atwood (16 April 2008). "Introducing". Coding Horror. Archived from the original on 3 February 2010. Retrieved 11 March 2009.
  6. ^ Jeff Atwood (10 September 2008). "None of Us is as Dumb as All of Us". Coding Horror. Archived from the original on 14 March 2009. Retrieved 11 March 2009.
  7. ^ Alan Zeichick (15 April 2009). "Secrets of social site success". SD Times. Archived from the original on 26 April 2009. Retrieved 16 April 2009.
  8. ^ "Spolsky's Software Q-and-A Site". Slashdot. 16 September 2008. Archived from the original on 16 May 2009. Retrieved 23 May 2009.
  9. ^ Joel Spolsky (25 April 2009). "Google Tech Talks: Learning from". YouTube. Archived from the original on 4 May 2019. Retrieved 23 May 2009.
  10. ^ Dummett, Ben (2 June 2021). "Stack Overflow Sold to Tech Giant Prosus for $1.8 Billion". Wall Street Journal. Retrieved 2 June 2021.
  11. ^ Jeff Atwood (21 September 2008). "The Gamification". Coding Horror Blog. Archived from the original on 1 February 2014. Retrieved 24 January 2011.
  12. ^ "Were Rewarding the Question Askers". Archived from the original on 16 November 2019. Retrieved 20 November 2019.
  13. ^ "What is reputation? How do I earn (and lose) it?". Stack Overflow. Archived from the original on 9 June 2013. Retrieved 14 August 2010.
  14. ^ "List of privileges". Archived from the original on 14 February 2020. Retrieved 22 November 2017.
  15. ^ "All Sites – Stack Exchange". Retrieved 28 March 2021.
  16. ^ "All Sites – Stack Exchange". Retrieved 28 March 2021.
  17. ^ "Stack Overflow Developer Survey 2021". Stack Overflow. Retrieved 22 July 2022.
  18. ^ "Tags". Stack Overflow. Archived from the original on 15 February 2020. Retrieved 9 December 2014.
  19. ^ Jeff Atwood (6 April 2008). "Help Name Our Website". Coding Horror. Archived from the original on 16 April 2015. Retrieved 15 July 2014.
  20. ^ "J.Atwood & J.Spolsky founding – but we need a logo". 30 April 2008. Archived from the original on 3 March 2016. Retrieved 23 May 2014.
  21. ^ Ha, Anthony (4 May 2010). "Stack Overflow raises $6M to take its Q&A model beyond programming". VentureBeat. Archived from the original on 21 April 2016. Retrieved 23 May 2014. The money we've raised means that, for the next ($6m / monthly burn rate) months, we can take on new projects, hire new people, and build new expert Q&A sites on a wide variety of new topics. Instead of opening sites in exchange for money, we're about to launch a new, democratic system where anyone can propose a Q&A site, and, if it gets a critical mass of interested people, we'll create it.
  22. ^ Fried, Ina (25 September 2019). "Axios Login: Take Note". Axios. Archived from the original on 10 May 2020. Retrieved 26 February 2020.
  23. ^ Dummett, Ben (2 June 2021). "Stack Overflow Sold to Tech Giant Prosus for $1.8 Billion". Wall St. Journal. Retrieved 2 June 2021.
  24. ^ Cimpanu, Catalin. "Stack Overflow says hackers breached production systems". ZDNet. Archived from the original on 7 December 2019. Retrieved 22 June 2019.
  25. ^ Ferguson, Mary (17 May 2019). "Update to Security Incident [May 17, 2019]". Stack Overflow Blog. Retrieved 11 June 2022.
  26. ^ "How do I ask a good question?". Retrieved 26 April 2021.
  27. ^ "Closing changes: on hold, unclear, too broad, opinion-based, off-topic reasons, bye-bye to Too Localized". Archived from the original on 27 August 2019. Retrieved 19 March 2017.
  28. ^ "The war of the closes". 25 June 2013. Archived from the original on 3 August 2019. Retrieved 3 August 2019.
  29. ^ "Dr. Strangedupe: Or, How I Learned to Stop Worrying And Love Duplication". 16 November 2010. Archived from the original on 12 August 2016. Retrieved 19 March 2017.
  30. ^ "Case Studies/". Archived from the original on 2 May 2015. Retrieved 19 March 2017.
  31. ^ Wang, Shaowei; David Lo; Lingxiao Jiang (18–22 March 2013). "An Empirical Study on Developer Interactions in StackOverflow" (PDF). Singapore Management University. Archived (PDF) from the original on 2 February 2015. Retrieved 25 February 2014.
  32. ^ Ford, Denae; Lustig, Kristina; Banks, Jeremy; Parnin, Chris (2018). ""We Don'T Do That Here": How Collaborative Editing with Mentors Improves Engagement in Social Q&A Communities". Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems. CHI '18. New York, NY, USA: ACM: 608:1–608:12. doi:10.1145/3173574.3174182. ISBN 9781450356206. S2CID 4758001.
  33. ^ Mamykina, Lena; Bella Manoim; Manas Mittal; George Hripcsak; Björn Hartmann (2011). "Design lessons from the fastest q&a site in the west". CHI '11 Proceedings of the SIGCHI Conference on Human Factors in Computing Systems: 2857–2866. doi:10.1145/1978942.1979366. ISBN 9781450302289. S2CID 8706419. Archived from the original on 5 March 2014. Retrieved 25 February 2014.
  34. ^ "Turbocharging the Roomba: solutions for premature deletion". Archived from the original on 14 February 2021. Retrieved 19 March 2017.
  35. ^ a b Bosu, Amiangshu; Christopher S. Corley; Dustin Heaton; Debarshi Chatterji; Jeffrey C. Carver; Nicholas A. Kraft (2013). "Building Reputation in StackOverflow: An Empirical Investigation" (PDF). Tuscaloosa, AL 35487-0290, USA: Department of Computer Science, The University of Alabama. Archived (PDF) from the original on 11 February 2015. Retrieved 11 February 2015.{{cite web}}: CS1 maint: location (link)
  36. ^ "What posts get deleted, and why?". Meta.StackOverflow. 3 January 2017. Archived from the original on 20 October 2020. Retrieved 19 March 2017.
  37. ^ Jeff Atwood (21 September 2008). "What Was Stack Overflow Built With?". Stack Overflow Blog. Archived from the original on 26 April 2016. Retrieved 23 May 2009.
  38. ^ Sam Saffron (30 March 2011). "How I learned to stop worrying and write my own ORM". Archived from the original on 2 August 2014. Retrieved 22 July 2014.
  39. ^ "Why should I create an account? – Help Center". Stack Overflow. Retrieved 28 March 2021.
  40. ^ Kastrenakes, Jacob (20 May 2020). "Here are all the winners of the 2020 Webby Awards". The Verge. Archived from the original on 21 May 2020. Retrieved 22 May 2020.
  41. ^ Brooke, Siân. ""Condescending, Rude, Assholes": Framing gender and hostility on Stack Overflow" (PDF).
  42. ^ Y. Acar, M. Backes, S. Fahl, D. Kim, M. L. Mazurek and C. Stransky, "You Get Where You're Looking for: The Impact of Information Sources on Code Security Archived 14 February 2021 at the Wayback Machine," 2016 IEEE Symposium on Security and Privacy (SP), San Jose, CA, 2016, pp. 289–305. doi: 10.1109/SP.2016.25

External links

Original content from Wikipedia, shared with licence Creative Commons By-Sa - Stack Overflow