WhatsApp Messenger, or simply WhatsApp, is an internationally available freeware, cross-platform centralized instant messaging (IM) and voice-over-IP (VoIP) service owned by American company Meta Platforms (formerly Facebook).^[11] It allows users to send text and voice messages,^[12] make voice and video calls, and share images, documents, user locations, and other content.^[13][14] WhatsApp's client application runs on mobile devices, and can be accessed from computers.^[15] The service requires a cellular mobile telephone number to sign up.^[16] In January 2018, WhatsApp released a standalone business app called WhatsApp Business which can communicate with the standard WhatsApp client.^[17][18]

The client application was created by WhatsApp Inc. of Mountain View, California, which was acquired by Facebook in February 2014 for approximately US$19.3 billion.^[19][20] It became the world's most popular messaging application by 2015,^[21][22] and had more than 2 billion users worldwide by February 2020.^[23] By 2016 it had become the primary means of Internet communication in regions including Latin America, the Indian subcontinent, and large parts of Europe an