For this idea, Huffman and Ohanian were accepted in Y Combinator's first class. Supported by the funding from Y Combinator, Huffman coded the site in Common Lisp and together with Ohanian launched Reddit in June 2005.

The idea and initial development of Reddit originated with then college roommates Steve Huffman and Alexis Ohanian in 2005.

Between November 2005 and January 2006, Reddit merged with Aaron Swartz's company Infogami, and Swartz became an equal owner of the resulting parent company, Not A Bug.

The team expanded to include Christopher Slowe in November 2005.

Reddit was originally written in Common Lisp but was rewritten in Python in December 2005.

Condé Nast (the publisher) acquires Reddit for less than $20 million. Team moves to San Francisco.

Huffman and Ohanian sold Reddit to Condé Nast Publications, owner of Wired, on October 31, 2006, for a reported $10 million to $20 million, and the team moved to San Francisco.

In November 2006, Swartz blogged complaining about the new corporate environment, criticizing its level of productivity.

In January 2007, Swartz was fired for undisclosed reasons.

After Huffman and Ohanian left Reddit, Erik Martin, who joined the company as a community manager in 2008 and later became general manager in 2011, played a role in Reddit's growth.

Reddit becomes open-source.

Huffman and Ohanian left Reddit in 2009.

Reddit launched two different ways of advertising on the site in 2009. The company launched sponsored content and a self-serve ads platform that year.

As of November 10, 2009, Reddit used Pylons as its web framework.

Reddit launched its Reddit Gold benefits program in July 2010, which offered new features to editors and created a new revenue stream for the business that did not rely on banner ads.

In 2010, Reddit released its first mobile web interface for easier reading and navigating the website on touch screen devices.

By February 2011, Reddit reached 1 billion page views per month.

On September 6, 2011, Reddit became operationally independent of Condé Nast, operating as a separate subsidiary of its parent company, Advance Publications.

Reddit and other websites participated in a 12-hour sitewide blackout on January 18, 2012, in protest of the Stop Online Piracy Act.

In May 2012, Reddit joined the Internet Defense League, a group formed to organize future protests.

Yishan Wong joined Reddit as CEO in 2012.

Reddit reached 1 billion page views per month. Within a year, Reddit again doubled in pageviews and reached 2 billion page views per month.

Reddit achieves 37 billion page views in 2012.

Reddit began accepting the digital currency Bitcoin for its Reddit Gold subscription service through a partnership with the bitcoin payment processor Coinbase in February 2013.

Reddit achieves 56 billion page views in 2013.

Wong resigned from Reddit in 2014, citing disagreements about his proposal to move the company's offices from San Francisco to nearby Daly City.

Ellen Pao replaced Wong as interim CEO in 2014 and resigned in 2015 amid a user revolt over the firing of a popular Reddit employee.

Reddit achieves 71.25 billion page views in 2014.

After five years away from the company, Ohanian and Huffman returned to leadership roles at Reddit: Ohanian became the full-time executive chairman in November 2014 following Wong's resignation.

Yishan Wong resigns as Reddit CEO. Ellen Pao becomes interim CEO and co-founder Alexis Ohanian returns to Reddit and becomes executive chairman.

On July 10, 2015, Pao resigned as CEO and was replaced by Reddit co-founder Steve Huffman.

Pao's departure on July 10, 2015, led to Huffman's return as the company's chief executive.

Reddit hires Marty Weiner, Founding Engineer at Pinterest, as its first Chief Technology Officer.

Reddit launches Upvoted, a news site that digs out interesting content from Reddit, but without enabling commenting.

In April 2016, Reddit launches a new blocking tool in an attempt to curb online harassment. The tool allows a user to hide posts and comments from selected Redditors in addition to blocking private messages from those Redditors.

Reddit removed Alien Blue and released its official application, Reddit: The Official App, on Google Play and the iOS App Store in April 2016.

In 2016, Reddit began hosting images using a new image uploading tool, a move that shifted away from the uploading service Imgur that had been the de facto service.

Reddit announces that its main code repositories, backing its desktop and mobile websites, are no longer open source.

Slowe, the company's first employee, rejoined Reddit in 2017 as chief technology officer.

Reddit's largest round of funding came in 2017 when the company raised $200 million and was valued at $1.8 billion. The funding supported Reddit's site redesign and video efforts.

In 2017, Reddit developed its own real-time chat software for the site.

Reddit's in-house video uploading service for desktop and mobile was launched in 2017.

Reddit was an open-source project from June 18, 2008, until 2017.

After Huffman rejoined Reddit as CEO, he launched Reddit's iOS and Android apps, fixed Reddit's mobile website and created A/B testing infrastructure. The company launched a major redesign of its website in April 2018.

The company launched a major redesign of its website in April 2018.

Reddit announces the rollout of a new design for the site and its logo Snoo.

Reddit Gold was renamed Reddit Premium in 2018. In addition to gold coins, users can gift silver and platinum coins to other users as rewards for quality content.

Reddit opened a Chicago office to be closer to major companies and advertising agencies located in and around Chicago.

Reddit launched its redesigned website in 2018, with its first major visual update in a decade.

In 2019, Reddit hired former Twitter ad director Shariq Rizvi as its vice president of ad products and engineering.

On June 5, 2020, Ohanian resigned from the board and planned to be replaced "by a Black candidate".

On June 5, 2020, Alexis Ohanian resigned as a member of the board in response to the George Floyd protests and requested to be replaced "by a Black candidate".

Reddit acquires Dubsmash. They intend to integrate its video creation tools into Reddit.

On March 5, 2021, Reddit announced that it had appointed Drew Vollero, who has worked at Snapchat's parent company Snap as its first Chief Financial Officer weeks after the site was thrust into the spotlight due to its role in the GameStop trading frenzy.

As of August 2021, Reddit is valued at more than $10 billion dollars following a $410 million funding round.