I often use my phone as hotspot on my laptop and use WhatsApp desktop application. Sometimes I leave WhatsApp on for many minutes (guesssing here; up to 2 hours).
I've recently figured out that WhatsApp consumes too much data and since I'm using my phone's data, how much it consumes matters.
I've experimented and recorded the network traffic. You can watch the video where I show this consumption.
In one instance (on the video), the app consumes ~20 MB/min while idle (not logged in), and ~33MB/min when logged in.
I was not paying attention to the rates while recording the video, so I decided to explicitly record the rates after the video.
In the second instance, it was ~10MB/min while idle, and ~14MB when logged in.
So, the app consumes 10-20 MB/min while idle, and 15-30 MB/min (idle × 1.5) when logged in.
I did not test any other IM app to compare with WhatsApp, but these rates seem like extreme to me.
Does anybody have an idea why it comsumes this much? Is there a way to prevent this? If not, I'll probably not use it when using my phone as a hotspot.
Update: This is an old question, and things got in the way and I didn't actively monitor it… What I found out later is WhatsApp application on the website is (currently) 133 MB (compressed), and it's 745 MB (uncompressed?) on my PC. When WhatsApp starts updating (Update.exe), it doesn't download the file that's on the site (133MB). Instead it downloads/updates uncompressed files and this takes 500+ MB. Whenever WhatsApp starts sucking my quota up like this, I just close the app, download and install the compressed version on the site. So doing a manual update solves the problem.
Best Answer
You should certainly not use the WhatsApp Web application, but rather use it in a regular webbrowser (Since the application does nothing else than displaying a webpage). Then you might use developer tools to measure the network traffic of that web application.
For example, use Firefox and open the Developer console by ctrl + shift + c. Then click the
Network-tab to open the network monitor. It should list all transferred objects with their size and transfer duration. You can even sort bySizeorTransferredto view what transfers have the biggest impact on your data. It shows the total amount of data transferred at the bottom, so you can make sure it's really the WhatsApp Web application that causes the high amount of traffic, and not something else. Then do your tests again, e.g. idle around in WhatsApp web or use it for some time. Maybe the issues even get fixed by using a regular browser, since it supports better caching etc.Furthermore, keep in mind that WhatsApp Web is seemingly not a well-written web application. I often noticed it uses a lot (e.g. 200% of 400%) of my notebooks CPU while doing nothing, and nearly all of it while loading messages or contacts. So don't be surprised if it's just a bug and you can't do anything about it. For me, at least, WhatsApp Web does not do any traffic while idling, at least when logged in.
Update: In case you really need to monitor the WhatsApp Web desktop application, you might want to use some advanced tools like Wireshark to capture traffic on your network interfaces. It allows you to see all network packets going through your connection, and you can filter by lots of criteria. This might give you some insight on what WhatsApp Web Desktop really does in the background. Still, you are not able to look into SSL connections, so in that case it gets a bit trickier. But since there are no advantages of the desktop application over the web application, I'd recommend using the web application instead.