Which phones will not be supported by WhatsApp in 2018?

Facebook-owned instant messaging platform WhatsApp will end support for smartphones running on BlackBerry OS, BlackBerry 10, and Windows Phone 8.0 and older, from December 31, 2017. WhatsApp will also end support for phones running on Nokia S40 operating system from next year. However, users with phones running the Android versions 2.3.7 and older can use WhatsApp until February 1, 2020.