Stack Overflow

Last updated

Stack Exchange, Inc.
Stack Overflow logo.svg
Stack Overflow Home.png
Screenshot of Stack Overflow in November 2020
Type of site
Knowledge market
Question and answer
Available inEnglish, Spanish, Russian, Portuguese, and Japanese
Owner Stack Exchange, Inc.
Created by Jeff Atwood and Joel Spolsky
CEOPrashanth Chandrasekar
URL OOjs UI icon edit-ltr-progressive.svg
Launched15 September 2008;12 years ago (2008-09-15) [1]
Current statusOnline
Content license
CC BY-SA 2.5, 3.0, or 4.0 (depending on date) [2]
Written in C# [3]

Stack Overflow is a question and answer site for professional and enthusiast programmers. It is a privately held website, the flagship site of the Stack Exchange Network, [4] [5] [6] 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 sites such as Experts-Exchange. The name for the website was chosen by voting in April 2008 by readers of Coding Horror, Atwood's popular programming blog. [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 and edit questions and answers in a fashion similar to a wiki or Reddit. [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 site. Users unlock new privileges with an increase in reputation like the ability to vote, comment, and even edit other people's posts. [16] 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] [17]

Closing questions is a main differentiation from other Q&A sites like Yahoo! Answers and a way to prevent low quality questions. [18] The mechanism was overhauled in 2013; questions edited after being put "on hold" now appear in a review queue. [19] 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. [20]

As of March 2021 Stack Overflow has over 14 million registered users, [21] and has received over 21 million questions and 31 million answers. [22] 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. [23]

Stack Overflow also has a Jobs section to assist developers in finding their next opportunity. [24] For employers, Stack Overflow provides tools to brand their business, advertise their openings on the site, and source candidates from Stack Overflow's database of developers who are open to being contacted. [25]


The website was created by Jeff Atwood and Joel Spolsky in 2008. [7] 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. [26]

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. [27]

In 2019, Stack Overflow named Prashanth Chandrasekar as its chief executive officer and Teresa Dietrich as its chief product officer. [28]

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 250 public network users were affected by this breach, which "could have returned IP address, names, or emails". [29]


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. [30] 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. [31] As of 2011, 92% of the questions were answered, in a median time of 11 minutes. [32] 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. [33]

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. [34] 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. [34]

In 2016, 1.5 million posts were deleted, of which about 8% were deleted by moderators. [35]

Content criteria

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. [36]


Stack Overflow is written in C# [3] using the ASP.NET MVC (Model-View-Controller) framework, and Microsoft SQL Server for the database [37] and the Dapper object-relational mapper used for data access. [38] 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. [39]


Stack Overflow won the 2020 Webby People's Voice Award for Community in the category Web. [40] This followed the success of Tumblr and Petfinder in previous years.

The site's culture has been criticized for being needlessly harsh, abrasive, and unfriendly, [41] [42] [ better source needed ] something which has been recognized by several Stack Overflow employees. [43] [ better source needed ] [44]

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. [45]

See also

Related Research Articles

Joel Spolsky American software engineer and writer

Avram Joel Spolsky is a software engineer and writer. He is the author of Joel on Software, a blog on software development, and the creator of the project management software Trello. He was a Program Manager on the Microsoft Excel team between 1991 and 1994. He later founded Fog Creek Software in 2000 and launched the Joel on Software blog. In 2008, he launched the Stack Overflow programmer Q&A site in collaboration with Jeff Atwood. Using the Stack Exchange software product which powers Stack Overflow, the Stack Exchange Network now hosts over 170 Q&A sites., formerly known as WikiAnswers, is an Internet-based knowledge exchange. The domain name was purchased by entrepreneurs Bill Gross and Henrik Jones at idealab in 1996. The domain name was acquired by NetShepard and subsequently sold to GuruNet and then AFCV Holdings. The website is now the primary product of the Answers Corporation. It has tens of millions of user-generated questions and answers, and provides a website where registered users can interact with one another.

Markdown Plain text markup language

Markdown is a lightweight markup language for creating formatted text using a plain-text editor. John Gruber and Aaron Swartz created Markdown in 2004 as a markup language that is appealing to human readers in its source code form. Markdown is widely used in blogging, instant messaging, online forums, collaborative software, documentation pages, and readme files.

Experts Exchange (EE) is a website for people in information technology (IT) related jobs to ask each other for tech help, receive instant help via chat, hire freelancers, and browse tech jobs. Controversy has surrounded their policy of providing answers only via paid subscription.

Yahoo! Answers was a community-driven question-and-answer (Q&A) website or knowledge market owned by Yahoo! where users would ask questions and answer those submitted by others, and upvote them to increase their visibility. Questions are organised into categories with multiple sub-categories under each to cover every topic users may ask questions on, such as beauty, business, finance, cars, electronics, entertainment, games, gardening, science, news, politics, parenting, pregnancy, and travel.

Reputation systems are programs or algorithms that allow users to rate each other in online communities in order to build trust through reputation. Some common uses of these systems can be found on E-commerce websites such as eBay,, and Etsy as well as online advice communities such as Stack Exchange. These reputation systems represent a significant trend in "decision support for Internet mediated service provisions". With the popularity of online communities for shopping, advice, and exchange of other important information, reputation systems are becoming vitally important to the online experience. The idea of reputation systems is that even if the consumer can't physically try a product or service, or see the person providing information, that they can be confident in the outcome of the exchange through trust built by recommender systems.

Visual Basic Event-driven programming language

Visual Basic is a third-generation event-driven programming language from Microsoft known for its Component Object Model (COM) programming model first released in 1991 and declared legacy during 2008. Microsoft intended Visual Basic to be relatively easy to learn and use. Visual Basic was derived from BASIC and enables the rapid application development (RAD) of graphical user interface (GUI) applications, access to databases using Data Access Objects, Remote Data Objects, or ActiveX Data Objects, and creation of ActiveX controls and objects.

Glitch (company) American software company

Glitch is a software company specializing in project management tools. Its products include project management and content management, and code review tools.

Jeff Atwood American software developer/author/blogger/entrepreneur

Jeff Atwood is an American software developer, author, blogger, and entrepreneur. He writes the computer programming blog Coding Horror. He co-founded the computer programming question-and-answer website Stack Overflow and co-founded Stack Exchange, which extends Stack Overflow's question-and-answer model to subjects other than programming.

MathOverflow is a mathematics question-and-answer (Q&A) website, which serves as an online community of mathematicians. It allows users to ask questions, submit answers, and rate both, all while getting merit points for their activities. It is a part of the Stack Exchange Network.

Quora Question-and-answer platform

Quora is an American question-and-answer website where questions are asked, answered, followed, and edited by Internet users, either factually or in the form of opinions. Its owner, Quora Inc., is based in Mountain View, California, United States.

Stack Exchange is a network of question-and-answer (Q&A) websites on topics in diverse fields, each site covering a specific topic, where questions, answers, and users are subject to a reputation award process. The reputation system allows the sites to be self-moderating. As of August 2019, the three most actively-viewed sites in the network are Stack Overflow, Super User, and Ask Ubuntu.

Ask Ubuntu

Ask Ubuntu is a community-driven question and answer website for the Ubuntu operating system. It is part of the Stack Exchange Network, running the same software as Stack Overflow.

UserVoice is a San Francisco based Software-as-a-Service (SaaS) company creating customer engagement tools.

Askbot is open source software used to create question and answer oriented Internet forums. The site started on July 2009, initially similar to Stack Overflow or Yahoo! Answers. Based on CNPROG and some code written for OSQA, it is primarily developed and maintained by Evgeny Fadeev.

Q&A software is online software that attempts to answer questions asked by users. Q&A software is frequently integrated by large and specialist corporations and tends to be implemented as a community that allows users in similar fields to discuss questions and provide answers to common and specialist questions.

Brainly Educational technology company

Brainly is a Polish education technology company based in Kraków, Poland, with headquarters in New York City. It provides a peer-to-peer learning platform for students, parents, and teachers to ask and answer homework questions. The platform has elements of gamification in the form of motivational points and ranks. It encourages users to engage in the online community by answering other users’ questions. As of November 2020, Brainly reported having 350 million monthly users making it the world's most popular education app.

Visual Studio Code Free source code editor by Microsoft

Visual Studio Code is a freeware source-code editor made by Microsoft for Windows, Linux and macOS. Features include support for debugging, syntax highlighting, intelligent code completion, snippets, code refactoring, and embedded Git. Users can change the theme, keyboard shortcuts, preferences, and install extensions that add additional functionality.

PhysicsOverflow is a physics website that serves as a post-publication open peer review platform for research papers in physics, as well as a collaborative blog and online community of physicists. It allows users to ask, answer and comment on graduate-level physics questions, post and review manuscripts from ArXiv and other sources, and vote on both forms of content.

Lyndsey Scott American model, iOS mobile app software developer, and actress

Lyndsey Scott is an American model, software developer, and actress. She was the first African American model to sign an exclusive runway contract with Calvin Klein. Between modeling assignments for prestigious fashion houses like Gucci, Prada, and Victoria's Secret, she writes mobile apps for iOS devices. She has been credited for challenging the stereotypes about models and computer programmers, and for inspiring young women to code.


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