With Companion Mode, users can finally use their WhatsApp account on multiple phones. Previously, you would be logged out of your primary phone if you logged into your account on a different phone, but you could link up to four secondary devices limited to desktop apps and Android tablets with the multi-device feature.
Including your primary phone, that means you can now use your WhatsApp account on up to five devices at the same time. The quota of four devices includes web, desktop app, Android tablet, or companion phones, so you won’t be able to link your account to your desktop if you for some reason have four linked smartphones. All your messages, media, and even calls are synced across all linked devices and they are all still end-to-end encrypted. The only restrictions for companion phones are that you cannot use them to view live locations, create and view broadcast lists, or add or delete WhatsApp statuses.
You can log out of the account from the linked devices themselves or you can even log them out remotely from your primary phone in the linked devices setting. Linking a secondary phone is quite simple as you only need to tap on the menu in the top-right corner of the app on your Android device and open up “Link a device”, which will show you a QR code that can be scanned using your primary device. As of now, while you can use either an Android or an iPhone as your primary phone, you still can’t use iPhones as linked companion devices. Additionally, your primary device doesn’t even need to be online for you to use WhatsApp on your linked devices but if you don’t use the app on your primary phone for over 14 days, all your secondary devices will be automatically logged out. (Source: WhatsApp)
