How to filter your chatlist for unread messages
The chatlist unread filter allows you to quickly view all of your unread chats. To filter unread chats, you'll need to have the latest version of WhatsApp installed on your device.
On iPhone: Scroll down in the chatlist to reveal the search bar. Then, tap the filter icon. Tap the icon again to turn it off.
On Android: Tap the search bar, then press Unread. To turn off the filter, tap the X or delete key on your Android keyboard.
On Web and Desktop: Click the filter icon to the right of the search bar. To turn off the filter, click the icon again.
On the WhatsApp Business app for Web: Click the filter icon to the right of the search bar, then click Unread chats. To turn off the filter, click the icon again.
Note: This feature is not available on WhatsApp Business for iPhone.