According to the information on the WhatsApp FAQ section, WhatsApp will stop working on some of the iOS and Android devices, starting from January 1, 2021. And this will affect several Android and iOS phones that may not be able to run the app as the company will withdraw support for older versions of OS from next year.
From a statement by WhatsApp company, WhatsApp will only be compatible with phones running the Android 4.0.3 operating system or newer Android version as well as iPhones running on iOS 9 and newer.
All iPhone models starting from iPhone 4 will lose support for the messaging platform in the next few days. Others iOS devices to be affected includes the iPhone 4S, the iPhone 5, the iPhone 5S, the iPhone 6, and the iPhone 6S.
For Android devices it includes, HTC Desire, Motorola Droid Razr, LG Optimus Black, and the Samsung Galaxy S2 will lose WhatsApp support as 2020 ends.
These phones will need to update to at least iOS 9 or Android OS 4.0.3:
To check which OS an iPhone is running, click the Settings menu, tap to the General and Information option, Software and the users will be able to see the OS running on that particular iPhone.
Android users can head to Settings, then About Phone to see which Android version their smartphone is running on.