Introduction about watsaap

 2009–2014

WhatsApp was founded by Brian Acton and Jan Koum, former employees of Yahoo!. It was initially not intended to be used as a messaging app.

In January 2009, after Koum purchased an iPhone, he and Acton, keen to jump into what they saw foresaw as a newly burgeoning multi-million dollar app industry created by the Apple App Store, Koum came up with an idea for an app to provide dynamic information about the people listed in your address book: it would show statuses for each person, for example: "if you were on a call, your battery was low, or you were at the gym." Their discussions often took place at the home of Koum's Russian friend Alex Fishman in West San Jose. They realized that to take the idea further, they would need an iPhone developer. Fishman visited RentACoder.com, found Russian developer Igor Solomennikov, and introduced him to Koum.

Koum named the app WhatsApp to sound like "what's up". On February 24, 2009, he incorporated WhatsApp Inc. in California. However, when early versions of WhatsApp kept crashing, Koum considered giving up and looking for a new job. Acton encouraged him to wait for a "few more months".

In June 2009, when the app had been downloaded by only a handful of Fishman's Russian-speaking friends, Apple launched push notifications, allowing users to be pinged although not using a relevant app.

Koum updated WhatsApp so that everyone in the user's network would be notified when a user's status changed. This new facility, to Koum's surprise, was used by users to ping "each other with jokey custom statuses like, "I woke up late" or "I'm on my way."

Suddenly a new kind of instant messaging facility had been born out of the chance capability that users found more useful than the app's intended purpose. Fishman said "At some point it sort of became instant messaging ... We started using it as 'Hey how are you?' And then someone would reply." Jan watched the changing statuses on a Mac Mini at his town house in Santa Clara, and realized he had unintentionally created a messaging service."

WhatsApp 2.0 was released in August 2009 with a purpose-designed messaging component; the number of active users suddenly increased to 250,000.

Although Acton was working on another startup idea, he decided to join the company. In October 2009, Acton persuaded five former friends at Yahoo! to invest $250,000 in seed funding, and Acton became a co-founder and was given a stake. He officially joined WhatsApp on November 1. After months at beta stage, the application launched in November 2009 on the App Store, exclusively for the iPhone. Koum then hired a friend in Los Angeles, Chris Peiffer, to develop a BlackBerry version, which arrived two months later. Subsequently, WhatsApp for Symbian OS was added in May 2010, and for Android OS in August 2010. In 2010 Google made multiple acquisition offers for WhatsApp, which were all declined.

To cover the cost of sending verification texts to users, WhatsApp was changed from a free service to a paid one. In December 2009, the ability to send photos was added to the iOS version. By early 2011, WhatsApp was one of the top 20 apps in the U.S. Apple App Store.

In April 2011, Sequoia Capital invested about $8 million for more than 15% of the company, after months of negotiation by Sequoia partner Jim Goetz.

By February 2013, WhatsApp had about 200 million active users and 50 staff members. Sequoia invested another $50 million, and WhatsApp was valued at $1.5 billion. Some time in 2013 WhatsApp acquired Santa Clara-based startup SkyMobius, the developers of Vtok, a video and voice calling app.

In a December 2013 blog post, WhatsApp claimed that 400 million active users used the service each month.

2014–2015

On February 19, 2014, one year after a venture capital financing round at a $1.5 billion valuation, Facebook, Inc. (now Meta Platforms) announced it was acquiring WhatsApp for US$19 billion, its largest acquisition to date. At the time, it was the largest acquisition of a venture-capital-backed company in history. Sequoia Capital received an approximate 5,000% return on its initial investment. Facebook, which was advised by Allen & Co, paid $4 billion in cash, $12 billion in Facebook shares, and, advised by Morgan Stanley, an additional $3 billion in restricted stock units granted to WhatsApp's founders Koum and Acton. Employee stock was scheduled to vest over four years subsequent to closing. Days after the announcement, WhatsApp users experienced a loss of service, leading to anger across social media.

The acquisition was influenced by the data provided by Onavo, Facebook's research app for monitoring competitors and trending usage of social activities on mobile phones, as well as startups that were performing "unusually well".

The acquisition caused many users to try, or move to, other message services. Telegram claimed that it acquired 8 million new users; and Line, 2 million.

At a keynote presentation at the Mobile World Congress in Barcelona in February 2014, Facebook CEO Mark Zuckerberg said that Facebook's acquisition of WhatsApp was closely related to the Internet.org vision. A TechCrunch article said about Zuckerberg's vision:

The idea, he said, is to develop a group of basic internet services that would be free of charge to use – 'a 911 for the internet.' These could be a social networking service like Facebook, a messaging service, maybe search and other things like weather. Providing a bundle of these free of charge to users will work like a gateway drug of sorts – users who may be able to afford data services and phones these days just don't see the point of why they would pay for those data services. This would give them some context for why they are important, and that will lead them to pay for more services like this – or so the hope goes.

Three days after announcing the Facebook purchase, Koum said they were working to introduce voice calls. He also said that new mobile phones would be sold in Germany with the WhatsApp brand, and that their ultimate goal was to be on all smartphones.

In August 2014, WhatsApp was the most popular messaging app in the world, with more than 600 million users. By early January 2015, WhatsApp had 700 million monthly users and over 30 billion messages every day. In April 2015, Forbes predicted that between 2012 and 2018, the telecommunications industry would lose $386 billion because of "over-the-top" services like WhatsApp and Skype. That month, WhatsApp had over 800 million users. By September 2015, it had grown to 900 million; and by February 2016, one billion.

Voice calls between two accounts were added to the app in March and April 2015.

On November 30, 2015, the Android WhatsApp client made links to messaging service Telegram unclickable and uncopyable. Multiple sources confirmed that it was intentional, not a bug, and that it had been implemented when the Android source code that recognized Telegram URLs had been identified. Some considered it an anti-competitive measure; WhatsApp offered no explanation.

2016–2019

On January 18, 2016, WhatsApp's co-founder Jan Koum announced that it would no longer charge users a $1 annual subscription fee, in an effort to remove a barrier faced by users without payment cards. He also said that the app would not display any third-party ads, and that it would have new features such as the ability to communicate with businesses.

By June 2016, the company's blog reported more than 100 million voice calls per day were being placed on WhatsApp.

On November 10, 2016, WhatsApp launched a beta version of two-factor authentication for Android users, which allowed them to use their email addresses for further protection. Also in November 2016, Facebook ceased collecting WhatsApp data for advertising in Europe. Later that month, video calls between two accounts were introduced.

On February 24, 2017, (WhatsApp's 8th birthday), WhatsApp launched a new Status feature similar to Snapchat and Facebook stories.

On May 18, 2017, the European Commission announced that it was fining Facebook €110 million for "providing misleading information about WhatsApp takeover" in 2014. The Commission said that in 2014 when Facebook acquired the messaging app, it "falsely claimed it was technically impossible to automatically combine user information from Facebook and WhatsApp." However, in the summer of 2016, WhatsApp had begun sharing user information with its parent company, allowing information such as phone numbers to be used for targeted Facebook advertisements. Facebook acknowledged the breach, but said the errors in their 2014 filings were "not intentional".

In September 2017, WhatsApp's co-founder Brian Acton left the company to start a nonprofit group, later revealed as the Signal Foundation, which developed the WhatsApp competitor Signal. He explained his reasons for leaving in an interview with Forbes a year later. WhatsApp also announced a forthcoming business platform to enable companies to provide customer service at scale, and airlines KLM and Aeroméxico announced their participation in the testing. Both airlines had previously launched customer services on the Facebook Messenger platform.

In January 2018, WhatsApp launched WhatsApp Business for small business use.

In April 2018, WhatsApp co-founder and CEO Jan Koum announced he would be leaving the company. By leaving before November 2018, due to concerns about privacy, advertising, and monetization by Facebook, Acton and Koum gave up $1.3 billion in unvested stock options. Facebook later announced that Koum's replacement would be Chris Daniels.

Later in September 2018, WhatsApp introduced group audio and video call features. In October, the "Swipe to Reply" option was added to the Android beta version, 16 months after it was introduced for iOS.

On October 25, 2018, WhatsApp announced support for Stickers. But unlike other platforms WhatsApp requires third-party apps to add Stickers to WhatsApp.

On November 25, 2019, WhatsApp announced an investment of $250,000 through a partnership with Startup India to provide 500 startups with Facebook ad credits of $500 each.

In December 2019, WhatsApp announced that a new update would lock out any Apple users who hadn't updated to iOS 9 or higher and Samsung, Huawei, Sony and Google users who hadn't updated to version 4.0 by February 1, 2020. The company also reported that Windows Phone operating systems would no longer be supported after December 31, 2019. WhatsApp was announced to be the 3rd most downloaded mobile phone app of the decade 2010–2019.

Since 2020

In early 2020, WhatsApp launched its "dark mode" for iPhone and Android devices – a new design consisting of a darker palette. In March, WhatsApp partnered with the World Health Organization and UNICEF to provide messaging hotlines for people to get information on the 2019-2020 coronavirus pandemic. In the same month WhatsApp began testing a feature to help users find out more information and context about information they receive to help combat misinformation.

In October 2020, Whatsapp rolled out a feature allowing users to mute both individuals and group chats forever. The mute options are ‘8 hours', ‘1 week', and ‘Always'. The ‘Always' option replaced the ‘1 year' option that was originally part of the settings.

In January 2021, WhatsApp announced a new Privacy Policy allowing WhatsApp to share data with its parent company, Facebook; users who did not accept by February 8, 2021 would lose access to the app. This would not apply in the EU, since it violates the principles of GDPR. Facing criticism, WhatsApp postponed the update to May 15, 2021, but said they had no plans to limit functionality of or nag users who did not approve the new terms.