Official support for WhatsApp on Windows Phone operating systems ended on . While you can still find legacy .xap files for archival purposes, the app will no longer connect to WhatsApp servers, making it non-functional for messaging on these devices. The Current State of WhatsApp on Windows Phone
This site provides legacy .xap and .appx files for older devices, including WhatsApp for Windows Phone. How to Install a XAP File (Legacy Method) download whatsapp xap file for windows phone
To install these files, your device typically needs to be in Developer Mode or have an unlocked bootloader: Microsoft Learn Enable Developer Mode Settings > Update & Security > For Developers and select the developer option. Using a PC Windows Phone SDK 8.0/8.1 Deployment Tools Official support for WhatsApp on Windows Phone operating
If you’re dusting off an old Nokia Lumia and looking for a WhatsApp XAP file How to Install a XAP File (Legacy Method)
Yes, Windows 10 Mobile used the .Appx format. However, like the XAP version, the Windows 10 Mobile version of WhatsApp has also been discontinued and blocked from server access.
The Internet Archive is the gold standard for digital preservation. A search for "WhatsApp XAP" or "Windows Phone Apps" on Archive.org often yields results in the form of "Software" items.