A "face book" is a student directory featuring photos and personal information.In 2003, Harvard had only a paper version along with private online directories. Zuckerberg told the Crimson, "Everyone's been talking a lot about a universal face book within Harvard. I think it's kind of silly that it would take the University a couple of years to get around to it. I can do it better than they can, and I can do it in a week."

Zuckerberg built a website called "Facemash" in 2003 while attending Harvard University. The site was comparable to Hot or Not and used "photos compiled from the online facebooks of nine Houses, placing two next to each other at a time and asking users to choose the "hotter" person". Facemash attracted 450 visitors and 22,000 photo-views in its first four hours. The site was sent to several campus group list-servers, but was shut down a few days later by Harvard administration.

In mid-2004, Napster co-founder and entrepreneur Sean Parker—an informal advisor to Zuckerberg became company president.

In January 2004, Zuckerberg coded a new website, known as "TheFacebook", inspired by a Crimson editorial about Facemash, stating "It is clear that the technology needed to create a centralized Website is readily available ... the benefits are many." Zuckerberg met with Harvard student Eduardo Saverin, and each of them agreed to invest $1,000 in the site.

On February 4, 2004, Zuckerberg launched "TheFacebook", originally located at thefacebook.com.

Membership was initially restricted to students of Harvard College. Within a month, more than half the undergraduates had registered. Dustin Moskovitz, Andrew McCollum, and Chris Hughes joined Zuckerberg to help manage the growth of the website. In March 2004, Facebook expanded to Columbia, Stanford and Yale. and then to all Ivy League colleges, Boston University, New York University, MIT, and successively most universities in the United States and Canada.

In June 2004, the company moved to Palo Alto, California.

The company received its first investment In June 2004, from PayPal co-founder Peter Thiel.

In 2005, the company dropped "the" from its name after purchasing the domain name facebook.com for US$200,000. The domain had belonged to AboutFace Corporation.

In May 2005, Accel Partners invested $12.7 million in Facebook, and Jim Breyer added $1 million of his own money.

A high-school version of the site launched in September 2005.

By late 2007, Facebook had 100,000 pages on which companies promoted themselves.

In 2007, Facebook launched Facebook Pages for brands and celebrities to interact with their fanbase.

On October 24, 2007, Microsoft announced that it had purchased a 1.6% share of Facebook for $240 million, giving Facebook a total implied value of around $15 billion. Microsoft's purchase included rights to place international advertisements.

On July 20, 2008, Facebook introduced "Facebook Beta", a significant redesign of its user interface on selected networks. The Mini-Feed and Wall were consolidated, profiles were separated into tabbed sections, and an effort was made to create a cleaner look. Facebook began migrating users to the new version in September 2008.

In October 2008, Facebook announced that its international headquarters would locate in Dublin, Ireland.

China blocked Facebook in 2009.

A January 2009 Compete.com study ranked Facebook the most used social networking service by worldwide monthly active users

The "like" button, stylized as a "thumbs up" icon, was first enabled on February 9, 2009, and enables users to easily interact with status updates, comments, photos and videos, links shared by friends and advertisements.

Organization pages began rolling out in May 2009.

In June 2009, Facebook introduced a "Usernames" feature, allowing users to choose a unique nickname used in the URL for their personal profile, for easier searching and sharing.

In September 2009, Facebook said that it had achieved positive cash flow for the first time.

On September 26, 2006, Facebook opened to everyone at least 13 years old with a valid email address.

In 2010, Facebook opened its fourth office, in Hyderabad it's the first in Asia.

In 2010, the US National Security Agency began taking publicly posted profile information from Facebook, among other social media services.

In 2010, Facebook won the Crunchie "Best Overall Startup Or Product" award for the third year in a row.

On February 23, 2010, Facebook was granted a patent on certain aspects of its News Feed. The patent covers News Feeds in which links are provided so that one user can participate in the activity of another user. The sorting and display of stories in a user's News Feed is governed by the EdgeRank algorithm.

The like button was extended to comments in June 2010. In 2017, Facebook expanded Like into "Reactions", choosing among five pre-defined emotions, including "Love", "Haha", "Wow", "Sad" or "Angry".

The company announced 500 million users in July 2010.

In November 2010, based on SecondMarket Inc. (an exchange for privately held companies' shares), Facebook's value was $41 billion. The company had slightly surpassed eBay to become the third largest American web company after Google and Amazon.com.

On November 15, 2010, Facebook announced it had acquired the domain name FB.com from the American Farm Bureau Federation(AFBF) for an undisclosed amount.

On January 11, 2011, the Farm Bureau disclosed $8.5 million in "domain sales income", making the acquisition of FB.com one of the ten highest domain sales in history.

In February 2011, Facebook announced plans to move its headquarters to the former Sun Microsystems campus in Menlo Park, California.

In March 2011, it was reported that Facebook was removing about 20,000 profiles daily for violations such as spam, graphic content and underage use, as part of its efforts to boost cyber security.

Statistics showed that Facebook reached one trillion page views in the month of June 2011, making it the most visited website tracked by DoubleClick.

On July 29, 2011, Facebook announced its Bug Bounty Program that paid security researchers a minimum of $500 for reporting security holes. The company promised not to pursue "white hat" hackers who identified such problems.

Facebook Messenger is an instant messaging service and software application. It began as Facebook Chat in 2008, was revamped in 2010 and eventually became a standalone mobile app in August 2011, while remaining part of the user page on browsers.

Each registered user on Facebook has a personal profile that shows their posts and content. The format of individual user pages was revamped in September 2011 and became known as "Timeline", a chronological feed of a user's stories, including status updates, photos, interactions with apps and events.

On November 29, 2011, Facebook settled Federal Trade Commission charges that it deceived consumers by failing to keep privacy promises.

San Mateo County, California, became the top wage-earning county in the country after the fourth quarter of 2012 because of Facebook.

In April 2012, Facebook acquired Instagram for approximately US$1 billion in cash and stock.

Facebook's initial public offering came on May 17, 2012, at a share price of US$38. The company was valued at $104 billion, the largest valuation to that date.

On June 7, 2012, Facebook launched its App Center to help users find games and other applications.

Zuckerberg announced at the start of October 2012 that Facebook had one billion monthly active users, including 600 million mobile users, 219 billion photo uploads and 140 billion friend connections.

In October 2012 Facebook's monthly active users passed one billion, with 600 million mobile users, 219 billion photo uploads, and 140 billion friend connections. The 2 billion user mark was crossed in June 2017.

On January 15, 2013, Facebook announced Facebook Graph Search, which provides users with a "precise answer", rather than a link to an answer by leveraging data present on its site.

In March 2012, Facebook announced App Center, a store selling applications that operate via the website. The store was to be available on iPhones, Android devices, and mobile web users.

On April 3, 2013, Facebook unveiled Facebook Home, a user-interface layer for Android devices offering greater integration with the site.

On April 15, 2013, Facebook announced an alliance across 19 states with the National Association of Attorneys General, to provide teenagers and parents with information on tools to manage social networking profiles.

On April 19 Facebook modified its logo to remove the faint blue line at the bottom of the "F" icon. The letter F moved closer to the edge of the box.

Based on its 2012 income of $5 billion, Facebook joined the Fortune 500 list for the first time in May 2013, ranked 462.

On June 12, Facebook announced that it was introducing clickable hashtags to help users follow trending discussions, or search what others are talking about on a topic.

Facebook joined Alliance for Affordable Internet (A4AI) in October, as it launched.

On October 13, Facebook acquired Onavo, an Israeli mobile web analytics company.

Standard & Poor's added Facebook to its S&P 500 index on December 21.

In January 2014, over one billion users connected via a mobile device.

In February 2014, Facebook announced that it would be buying mobile messaging company WhatsApp for US$19 billion in cash and stock.

In February 2014, Facebook expanded the gender setting, adding a custom input field that allows users to choose from a wide range of gender identities. Users can also set which set of gender-specific pronoun should be used in reference to them throughout the site.

The company celebrated its 10th anniversary during the week of February 3, 2014.

On March 20, 2014, Facebook announced a new open-source programming language called Hack. Before public release, a large portion of Facebook was already running and "battle tested" using the new language.

In May 2014, Facebook introduced a feature to allow users to ask for information not disclosed by other users on their profiles. If a user does not provide key information, such as location, hometown, or relationship status, other users can use a new "ask" button to send a message asking about that item to the user in a single click.

As of June, mobile accounted for 62% of advertising revenue, an increase of 21% from the previous year.

By September Facebook's market capitalization had exceeded $200 billion.

Zuckerberg participated in a Q&A session at Tsinghua University in Beijing, China, on October 23, where he attempted to converse in Mandarin.

Zuckerberg hosted visiting Chinese politician Lu Wei, known as the "Internet czar" for his influence in China's online policy, on the 8th of December.

As of January 21, 2015, Facebook's algorithm was revised in an attempt to filter out false or misleading content, such as fake news stories and hoaxes.

On May 13, 2015, Facebook in association with major news portals launched "Instant Articles" to provide news on the Facebook news feed without leaving the site.

Facebook released its blueprints of Surround 360 camera on GitHub under an open-source license.

Following the 2016 presidential election, Facebook announced that it would combat fake news by using fact checkers from sites like FactCheck.org and Associated Press (AP), making reporting hoaxes easier through crowdsourcing, and disrupting financial incentives for abusers.

On April 12, 2016, Zuckerberg outlined his 10 year vision, which rested on three main pillars: artificial intelligence, increased global connectivity and virtual/augmented reality.

In June, Facebook announced Deep Text, a natural language processing AI that learns user intent and context in 20 languages.

In July, a US$1 billion suit was filed against the company alleging that it permitted Hamas to use it to perform assaults that cost the lives of four people.

In September, it won an Emmy for its animated short film "Henry".

In October, Facebook announced a fee-based communications tool called Workplace that aims to "connect everyone" at work. Users can create profiles, see updates from co-workers on their news feed, stream live video and participate in secure group chats.

Facebook opened it's London headquarters in 2017 in Fitzrovia in central London.

In January 2017, Facebook launched Facebook Stories for iOS and Android in Ireland. The feature, following the format of Snapchat and Instagram stories, allows users to upload photos and videos that appear above friends' and followers' News Feeds and disappear after 24 hours.

In 2017, Facebook added "Messenger Day", a feature that lets users share photos and videos in a story-format with all their friends with the content disappearing after 24 hours; Reactions, which lets users tap and hold a message to add a reaction through an emoji; and Mentions, which lets users in group conversations type @ to give a particular user a notification.

On January 17, 2017, Facebook COO Sheryl Sandberg planned to open Station F, a startup incubator campus in Paris, France.

On April 18, Facebook announced the beta launch of Facebook Spaces at its annual F8 developer conference. Facebook Spaces is a virtual reality version of Facebook for Oculus VR goggles.

In September, Facebook announced it would spend up to US$1 billion on original shows for its Facebook Watch platform.

On October 11, 2017, Facebook introduced the 3D Posts feature to allow for uploading interactive 3D assets.

On October 16, it acquired the anonymous compliment app tbh, announcing its intention to leave the app independent.

Facebook opened an office in Cambridge, Massachusetts in 2018.

Facebook ranked No. 76 in the 2018 Fortune 500 list of the largest United States corporations by revenue. Most comes from advertising. One analysis of 2017 data determined that the company earned US$20.21 per user from advertising.

On January 11, 2018, Facebook announced that it would change the News Feed to prioritize friends/family content and de-emphasize content from media companies.

Facebook customer Global Science Research sold information on over 87 million Facebook users to Cambridge Analytica, a political data analysis firm. According to The Guardian both Facebook and Cambridge Analytica threatened to sue the newspaper if it published the story. After publication, Facebook claimed that it had been "lied to". On March 23, 2018, The English High Court granted an application by the Information Commissioner's Office for a warrant to search Cambridge Analytica's London offices, ending a standoff between Facebook and the Information Commissioner over responsibility.

On March 25, Facebook published a statement by Zuckerberg in major UK and US newspapers apologizing over a "breach of trust".

On March 26, the Federal Trade Commission opened an investigation into the matter. The controversy led Facebook to end its partnerships with data brokers who aid advertisers in targeting users.

In May 2018, the government of Papua New Guinea announced that it would ban Facebook for a month while it considered the impact of the website on the country, though no ban has since occurred.

In May 2018 at F8, the company announced it would offer its own dating service.

On June 7, 2018 Facebook announced that a bug had resulted in about 14 million Facebook users having their default sharing setting for all new posts set to "public".

In July, Facebook was charged £500,000 by UK watchdogs for failing to respond to data erasure requests.

On July 18, Facebook established a subsidiary named Lianshu Science & Technology in Hangzhou City, China, with $30 million of capital. All its shares are held by Facebook Hong. Approval of the registration of the subsidiary was then withdrawn, due to a disagreement between officials in Zhejiang province and the Cyberspace Administration of China.

On July 26, Facebook became the first company to lose over $100 billion worth of market capitalization in one day, dropping from nearly $630 billion to $510 billion after disappointing sales reports.

On July 31, Facebook said that the company had deleted 17 accounts related to the 2018 American elections.

On September 19, Facebook announced that, for news distribution outside the United States, it would work with U.S. funded democracy promotion organizations, International Republican Institute and the National Democratic Institute, which are loosely affiliated with the Republican and Democratic parties.

On September 28, 2018, Facebook experienced a major breach in its security, exposing the data of 50 million users. The data breach started in July 2017 and was discovered on September 16.Facebook notified users affected by the exploit and logged them out of their accounts.

In November, Facebook launched smart displays branded Portal and Portal Plus (Portal+). They support Amazon's Alexa (intelligent personal assistant service). The devices include video chat function with Facebook Messenger.

In January 2019, the 10 year challenge was started asking users to post a photograph of themselves from 10 years ago (2009) and a more recent photo.

Criticized for its role in vaccine hesitancy, Facebook announced in March 2019 that it would provide users with "authoritative information" on the topic of vaccines.

In March 2019, Facebook confirmed a password compromise of millions of Facebook lite application users, however in April the company further stated that it was not just limited to Facebook but had also affected millions of Instagram users. The reason cited was the storage of password as plain text instead of encryption which could be read by its employees.

On March 14, Huffington Post reported that Facebook’s PR agency had paid someone to tweak Facebook COO Sheryl Sandberg’s Wikipedia page, as well as adding a page for the global head of PR, Caryn Marooney.

In March 2019, the perpetrator of the Christchurch mosque shootings in New Zealand used Facebook to stream live footage of the attack as it unfolded. Facebook took 29 minutes to detect the livestreamed video, which was eight minutes longer than it took police to arrest the gunman. About 1.3M copies of the video were blocked from Facebook but 300,000 copies were published and shared.

Further bans were made in mid-April 2019, banning several British far-right organizations and associated individuals from Facebook, and also banning praise or support for them.

On 4 April 2019, half a billion records of Facebook users were found exposed on Amazon cloud servers, containing information about users’ friends, likes, groups, and checked-in locations, as well as “names, passwords and email addresses.

On April 24, 2019, Facebook said it could face a fine between $3 billion to $5 billion as the result of an investigation by the Federal Trade Commission. The agency has been investigating Facebook for possible privacy violations, but has not announced any findings yet.

In early-April 2019, Facebook announced that it would be pulling its apps from Windows Phone on April 30, 2019, including Facebook, Messenger and Instagram.

In May 2019, Facebook founded Libra Networks, reportedly in order to develop their own stablecoin cryptocurrency. In recent developments it has been reported that Libra is being supported by financial companies like Visa, Mastercard, PayPal and Uber. The consortium of companies is expected to pool in $10 million each to fund the launch of the cryptocurrency coin named Libra.

On May 2, 2019 at F8, the company announced its new vision with the tagline "the future is private". A redesign of the website and mobile app was introduced, dubbed as "FB5". The event also featured plans for improving groups, a dating platform, end-to-end encryption on its platforms, and allowing users on Messenger to communicate directly with WhatsApp and Instagram users.

In late July 2019, the company announced it was under antitrust investigation by the Federal Trade Commission.

On July 3, 2019, Facebook's option to view and load pictures stopped working as people around the world complained. Facebook posted on Twitter about the issue and said they would resolve it as soon as they could.