WhatsApp starts testing multi-device capability and explains how it works

Facebook Engineering

WhatsApp is rolling out a limited public beta test for it's updated multi-device capability.

The company said it plans "to initially test the experience with a small group of users from our existing beta program," according to a post Wednesday on Facebook Engineering.

Cut through the chatter

Subscribe to CNET's Mobile newsletter for the latest phone news and reviews. With the beta, first teased in June, users will be able to use WhatsApp on a phone and up to four linked companion devices simultaneously, even if their phone battery dies. Each device connects to a user's WhatsApp independently and maintains end-to-end encryption. 

Facebook says it developed new technology to keep end-to-end encryption while also syncing data, such as contact names and chat archives, across devices. The current Whatsapp experience before this beta uses a phone as the primary device, and has companion devices mirror the phone's contents with their user interface. Because they rely on a phone to operate, companion devices are slower and frequently get disconnected. 

"The new WhatsApp multi-device architecture removes these hurdles, no longer requiring a smartphone to be the source of truth while still keeping user data seamlessly and securely synchronized and private," according to the post.

Whatsapp says it will continue optimizing performance and adding features to the new capability before rolling it out more broadly.

Eligible users can sign up for the beta in the WhatsApp help center