YouTube was founded by
Steve Chen and
Jawed Karim, who were all early employees of
 Hurley had studied design at
Indiana University of Pennsylvania, and Chen and Karim studied
computer science together at the
University of Illinois at Urbana-Champaign.
 According to a story that has often been repeated in the media, Hurley and Chen developed the idea for YouTube during the early months of 2005, after they had experienced difficulty sharing videos that had been shot at a dinner party at Chen's apartment in San Francisco. Karim did not attend the party and denied that it had occurred, but Chen commented that the idea that YouTube was founded after a dinner party "was probably very strengthened by marketing ideas around creating a story that was very digestible".
Karim said the inspiration for YouTube first came from
Janet Jackson's role in the 2004
Super Bowl incident, when her breast was exposed during her performance, and later from the
2004 Indian Ocean tsunami. Karim could not easily find video clips of either event online, which led to the idea of a video sharing site.
 Hurley and Chen said that the original idea for YouTube was a video version of an
online dating service, and had been influenced by the website
Hot or Not.
The YouTube logo from launch until 2011, featuring its former slogan Broadcast Yourself
YouTube began as a
venture capital-funded technology
startup, primarily from an $11.5 million investment by
Sequoia Capital between November 2005 and April 2006.
 YouTube's early headquarters were situated above a pizzeria and Japanese restaurant in San Mateo, California.
www.youtube.com was activated on February 14, 2005, and the website was developed over the subsequent months.
 The first YouTube video, titled
Me at the zoo, shows co-founder Jawed Karim at the
San Diego Zoo.
 The video was uploaded on April 23, 2005, and can still be viewed on the site.
 YouTube offered the public a beta test of the site in May 2005. The first video to reach one million views was a
Nike advertisement featuring
Ronaldinho in November 2005.
 Following a $3.5 million investment from Sequoia Capital in November, the site launched officially on December 15, 2005, by which time the site was receiving 8 million views a day.
 The site grew rapidly and, in July 2006, the company announced that more than 65,000 new videos were being uploaded every day, and that the site was receiving 100 million video views per day.
 According to data published by market research company
comScore, YouTube is the dominant provider of online video in the United States, with a
market share of around 43% and more than 14 billion views of videos in May 2010.
In May 2011, 48 hours of new videos were uploaded to the site every minute,
 which increased to 60 hours every minute in January 2012,
 100 hours every minute in May 2013,
 300 hours every minute in November 2014,
 and 400 hours every minute in February 2017.
 The site has 800 million unique users a month.
 It is estimated that in 2007 YouTube consumed as much
bandwidth as the entire Internet in 2000.
 According to third-party web analytics providers,
SimilarWeb, YouTube is the second-most visited website in the world, as of December 2016 ; SimilarWeb also lists YouTube as the top TV and video website globally, attracting more than 15 billion visitors per month.
The choice of the name
www.youtube.com led to problems for a similarly named website,
www.utube.com. The site's owner,
Universal Tube & Rollform Equipment, filed a lawsuit against YouTube in November 2006 after being regularly overloaded by people looking for YouTube. Universal Tube has since changed the name of its website to
 In October 2006,
Google Inc. announced that it had acquired YouTube for $1.65 billion in Google stock,
 and the deal was finalized on November 13, 2006.
YouTube's headquarters in San Bruno, California
In March 2010, YouTube began free streaming of certain content, including 60 cricket matches of the
Indian Premier League. According to YouTube, this was the first worldwide free online broadcast of a major sporting event.
 On March 31, 2010, the YouTube website launched a new design, with the aim of simplifying the interface and increasing the time users spend on the site. Google product manager Shiva Rajaraman commented: "We really felt like we needed to step back and remove the clutter."
 In May 2010, YouTube videos were watched more than two billion times per day.
 This increased to three billion in May 2011,
 and four billion in January 2012.
 In February 2017, one billion hours of YouTube was watched every day.
In October 2010, Hurley announced that he would be stepping down as chief executive officer of YouTube to take an advisory role, and that
Salar Kamangar would take over as head of the company.
 In April 2011, James Zern, a YouTube software engineer, revealed that 30% of videos accounted for 99% of views on the site.
 In November 2011, the
Google+ social networking site was integrated directly with YouTube and the
Chrome web browser, allowing YouTube videos to be viewed from within the Google+ interface.
YouTube logo from 2015 until 2017
In December 2011, YouTube launched a new version of the site interface, with the video channels displayed in a central column on the home page, similar to the news feeds of social networking sites.
 At the same time, a new version of the YouTube logo was introduced with a darker shade of red, the first change in design since October 2006.
 In May 2013, YouTube launched a pilot program to begin offering some content providers the ability to charge $0.99 per month or more for certain channels, but the vast majority of its videos would remain free to view.
 In February 2014,
Susan Wojcicki was appointed
CEO of YouTube.
In February 2015, YouTube released a secondary mobile app known as
YouTube Kids. The app is designed to provide an experience optimized for children, and features a simplified user interface, curated selections of channels featuring age-approriate content (including existing channels and entertainment brands), and parental control features.
 Later on August 26, 2015, YouTube launched YouTube Gaming—a
video gaming-oriented sub-site and app that is intended to compete with the
 2015 also saw the announcement of a premium YouTube service titled YouTube Red, which provides users with both ad-free content as well as the ability to download videos among other features.
 On August 10, 2015, Google announced that it was creating a new company,
Alphabet, to act as the
holding company for Google, with the change in financial reporting to begin in the fourth quarter of 2015. YouTube remains as a subsidiary of Google.
 In January 2016, YouTube expanded its headquarters in San Bruno by purchasing an office park for $215 million. The complex has 554,000 square feet of space and can house up to 2,800 employees.
On August 29, 2017, YouTube launched a new logo, typeface, color scheme and other changes to the appearance of its desktop and mobile app.