WeChat, a messenger app, is founded.[4] It eventually starts to compete with WhatsApp and becomes very popular in China.
Apr 2011
In Series A round, WhatsApp founders agree to take $7 million from Sequoia Capital on top of their $250,000 seed funding, after months of negotiation with Sequoia partner Jim Goetz.[1]
May 2011
Snapchat, a competing photo messaging app, is founded.[5]
Jan 6, 2012
An unknown hacker publishes a website that makes it possible to change the status of an arbitrary WhatsApp user, as long as the phone number was known.[6][7]
Aug 2012
The WhatsApp support staff announce that messages were encrypted in the "latest version" of the WhatsApp software for iOS and Android (but not BlackBerry, Windows Phone, and Symbian), without specifying the cryptographic method.[8]
Feb 2013
WhatsApp's user base grows to about 200 million active users and its staff to 50.[1]
Jul 2013
Sequoia invests another $50 million in Series B round, valuing WhatsApp at $1.5 billion.[9]
Jul 16, 2013
WhatsApp changes its profit model with an annual subscription fee of $1 after a free first year.[10][11]
Aug 2013
Telegram, a cloud-based instant messaging service, launches.[12]
Facebook, Inc. announces its acquisition of WhatsApp for US$19 billion, its largest acquisition to date.[14] Facebook pays $4 billion in cash, $12 billion in Facebook shares, and an additional $3 billion in restricted stock units granted to WhatsApp's founders.[15]
Mar 2014
Someone discovers a vulnerability in WhatsApp encryption on the Android application that allows another app to access and read all of a user’s chat conversations within it.[16]
Nov 2014
WhatsApp introduces Read Receipts, which show when a message is read by a recipient. Within a week, WhatsApp introduces an update allowing users to disable this feature.[17]
Jan 21, 2015
WhatsApp launches WhatsApp Web, a web client which can be used through a web browser by syncing with the mobile device's connection.[18]
Jan 21, 2015
WhatsApp announces its policy on cracking down on 3rd-party clients, including WhatsApp+.[19] Users would not be able to use WhatsApp’s services at all until the third-party apps are uninstalled.[20]
Dec 2015
WhatsApp is briefly shut down in Brazil after it refuses to place wiretaps on certain WhatsApp accounts.[21] It is shut down in Brazil again in May 2016 and in July 2016.[22]
Jan 18, 2016
Jan Koum announces that WhatsApp will no longer charge its users a $1 annual subscription fee.[23][24] There is still no clear plan for monetizing WhatsApp.[25]
Mar 2016
Diego Dzodan, a Facebook executive, is arrested by Brazilian federal police after Facebook fails to turn over information from his WhatsApp messaging account into a judge's request for a drug trafficking investigation.[26][27]
Mar 2, 2016
WhatsApp introduces its document-sharing feature, initially allowing users to share PDF files with their contacts.[28]
This article provides a detailed chronological account of the historical reception and criticism of security and privacy features in the WhatsApp messaging service.