If you do not have an unlimited plan, the ideal is to configure your WhatsApp to save the data from the internet, so that you do not lose your connection, we recommend that you attend to what we explain below.
Eye: to achieve this, you will have to make some changes in your general configuration.
To begin, downloading files / documents, and videos with data is heavier than simple images (which are generally reduced for WA), so you should restrict downloading these files automatically when you're not in a Wi-Fi connection.
To do this go to Settings / Settings and choose "Storage Data".
Once there, choose the file types you want to be downloaded automatically. I recommend that if you have a limited data load you choose to do it only with photos / images.
If we do not configure, our conversations are automatically backed up using cellular data, regardless of when we connect to a wifi, which could end your plan ahead of time.
To avoid this, follow the following route:
Go to Settings, follow Chats, then "Backup the chats" and choose only with Wi-Fi.
Go to Settings, follow Chats, then "Backup the chats" and choose if you want automatic security copies to be made or if you do not want them to happen.
Reduce the quality of calls
Although there are few who use WhatsApp calls, it reduces the quality of them in:
Settings, go to configuration, data and storage and finally, look for the option of calls.
You will have to look for the option to reduce the use of data in this function and that's it.