: Official backend support for Android 2.3.7 and older was entirely terminated.
You may find websites offering "WhatsApp for Gingerbread" APKs. . About supported operating systems | WhatsApp Help Center android 2.3 6 whatsapp download
Maintaining end-to-end encryption and modern security features requires newer system capabilities that older OS versions cannot provide. WhatsApp officially states that custom ROMs and rooted phones can compromise security features and allow other applications to potentially read your messages despite end-to-end encryption. : Official backend support for Android 2
WhatsApp servers require newer software to talk. About supported operating systems | WhatsApp Help Center
Meta cites two primary reasons for ending support for older operating systems:
While WhatsApp officially ended support for Android 2.3.6 (Gingerbread) years ago, many users with legacy devices still look for ways to stay connected. This guide covers the history of WhatsApp on Gingerbread, the risks of using outdated versions, and how to manage a legacy device today. The Evolution of WhatsApp and Android 2.3.6