: WhatsApp uses server-side "killswitches" that prevent outdated clients from connecting to the network. How to Find Older Versions (For Archival Purposes) WhatsApp Messenger (Android 4.1+) APKs - APKMirror

While you can technically download older APK files, using them is nearly impossible for the following reasons:

: Even if you install an older APK (like version 2.23.8.78), the app will typically fail to verify your phone number or display a "this version of WhatsApp became out of date" message.

: Legacy versions lack modern end-to-end encryption patches and security protocols required to connect to WhatsApp's servers.

WhatsApp Messenger APK for Android 4.1.2: Support and Compatibility Guide