Apps like Telegram allow, from its conception, to use it on as many devices as we want without problem. However, WhatsApp was forced to introduce WhatsApp Web and other web-based apps in order to fight Telegram. In the middle of 2020, it is still necessary to have Internet connection on mobile to be able to use it on the computer, but that will change soon.
WhatsApp continues to advance in use on multiple devices
The function is one of the most demanded by users of the application, and although WhatsApp is already quite advanced, its development is complex. At the moment we already know that the encryption key will be synchronized between devices in order to access all messages. He device limit will be four, although WhatsApp could expand it to more in the future in the same way that they have done with the participants of the video calls.
When we want to use WhatsApp on a second device, we must make a copy of the conversation history. To do this, the app will need WiFi connection, since there may be hundreds of megabytes of information to synchronize and we can melt the data rate in an oversight. Thus, once connected to the WiFi, we can start the synchronization process. Once finished, the messages will arrive at the same time to all the devices that we have synchronized. Every time a new device is added, the encryption key will change, and all paired devices will be notified of this change.
We can change the operating system without losing the chats
With this, for example, you can change mobile with greater ease to use WhatsApp, as well as change WhatsApp from Android to iOS or vice versa without fear of losing messages on the way as it currently happened. The only way to keep the current chats when changing mobile was if we did it to one with the same operating system, where for example in Android the chats are synchronized through Google Drive.
At the moment it is confirmed that use Android chats on iOS, but hopefully the reverse can also be done. In the past it was already known that WhatsApp was working to convert the iOS database to make it compatible with the format used in Android, so it seems clear that it will be available for both platforms.
About the launch of WhatsApp for iPad, the app has been delayed for a while because they want to launch it when the synchronization function is already available. This app was the first that showed that we would be able to use WhatsApp outside of mobile phones without depending on their having an Internet connection.