WhatsApp has announced that they have started to test multi-device capabilities. According to them, “With this new capability, you can now use WhatsApp on your phone and up to four other nonphone devices simultaneously — even if your phone battery is dead. Each companion device will connect to your WhatsApp independently while maintaining the same level of privacy and security through end-to-end encryption that people who use WhatsApp have come to expect.”
The company goes on to kind of explain why this feature took so long, one of which had to do with security where prior to multi-device support, all WhatsApp users were identified by a single identity key. They have since expanded on that where now each device has its own identity key that verifies that they are who they say they are.
At the moment, multi-device is still a feature in testing and only a small group of users will get to try it out in the beta, but it’s only a matter of time before it is expanded to include more users before it finally goes public.