I signed up to WhatsApp, and wanted to use its web access to IM with a friend who is travelling and will connect her Android phone to wifi hotspot when she can.

I assumed WhatsApp would send/receive IM messages over the Net for free (me on a computer, her through a wifi hotpost), but here's a screenshot of WhatsApp Web:

enter image description here

FWIW, my phone is connected to my computer through USB, but the whole point of using WhatsApp is to avoid being charged for SMS text messages.

So, is using WhatsApp between an ADSL-connected Windows computer and a wifi-connect Android smartphone free or not?

Thank you.

  • You phone is connected to your PC to I assume to charge the battery not provide it internet. You need to your phone to a wireless access point have you done that.
    – Ramhound
    Jul 3, 2016 at 20:37
  • It says it connects to the phone to "sync" messages, presumably it does that as a convenience so you can see earlier messages (sent/received on the phone itself) on the web interface. I doubt they actually send messages through your phone as that would be pretty useless since Whatsapp goes through the internet anyway, so why not directly send them instead of proxying them through your phone? Jul 4, 2016 at 1:15
  • 3
    @AndréBorie This seems annoying at first, but makes sense once you remember WhatsApp uses end-to-end encryption, and the encryption keys never leave your phone. With this security model, everything has to go through the phone, or we'd have a huge security problem. The competitor Telegram can send directly from the web client, but doesn't use end to end encryption by default (its secret chats can only be read on the client which started it).
    – amon
    Jul 4, 2016 at 5:29
  • Related article: How does the new WhatsApp web client work?
    – Sayse
    Jul 4, 2016 at 10:53
  • 1
    These links are worth reading: blog.whatsapp.com/614/WhatsApp-Web censore.blogspot.nl/2015/01/… Thanks to @Sayse for finding the articles. I've put them here so you don't have to visit that horrible Quora site. Jul 4, 2016 at 10:58

3 Answers 3


The only thing WhatsApp for Web does, is continuously query the WhatsApp on your phone and interact with it. You can type message using the website, but they are only delivered once they arrive on your phone, and your phone then confirms the arrival of the message.

So using WhatsApp for Web is basically the same as when you use it on your phone, except that its more convenient because you do not have to keep looking at your phone, and typing is a lot easier.

That being said, WhatsApp uses the internet to send and receive messages, not SMS text messages. How you have your phone connected to the internet will determine how the WhatsApp messages are being sent. If your phone is connected to your local WiFi spot, and as such, you don't use your cellular internet for which you pay, then using WhatsApp is free. If you have not connected your phone to wifi, then in addition to using regular WhatsApp, you also have to keep in mind, that your web session will interact with your phone through the internet for which additional data is being generated.

  • This is strange: I unplugged the phone from the PC (USB), and I could still send a message through WhatsAPP Web (through Ethernet. I don't need wifi at home). So it looks like WhatsApp Web does send messages directly, not through the phone (how would it do it anyway, withouth installing some driver between the browser on the PC and the smartphone on USB?). Jul 4, 2016 at 10:45
  • 4
    WhatsApp is using the Internet to communicate with your computer. So it doesn't need a USB-cable. Your PC can still connect to your phone when they're both connected to the Internet. Jul 4, 2016 at 10:55
  • Ok, so, like I thought, messages from WhatsUp web don't go through the phone, unlike what it says in the screenshot I posted Jul 4, 2016 at 11:02
  • 2
    So if I understood correctly, sending a message from the web version, the path it follows is: My PC -> WhatsApp Server -> My Phone -> WhatsApp Server -> Recipient?
    – George T
    Jul 4, 2016 at 12:01
  • Yeah. More precise, the server checks with the phone and when the message is delivered to the phone, the server also delivers it to the client. So it does not send it twice.
    – LPChip
    Jul 4, 2016 at 12:55

WhatsApp communicates through the Internet, not SMS (mobile text messages).

The question whether it ends up being free depends on the amount of bandwidth on your home and mobile plans, as well as how much you use it. This type of application typically uses very little bandwidth and isn't normally a source of worry.


WhatsApp web only connects if your PC and phone are connected to the same Wi-Fi network (this could be your phone acting as a hotspot to your PC, in which case you may pay data charges) The web interface sends and receives WhatsApp messages through your phone, so if your phone is connected to your home broadband via Wi-Fi then you will pay no charges.

  • 1
    This is not true. If your phone uses 3G or 4G while your computer uses internet through a LAN or WIFI port, it will still work. As long as your computer can communicated with your phone over internet, everything works.
    – LPChip
    Jul 4, 2016 at 7:26
  • 3
    Your "your-you're" score: 4 out of 5. No, it's not enough.
    – Sharky
    Jul 4, 2016 at 9:13
  • Edited. Happy, @Sharky? :)
    – LPChip
    Jul 4, 2016 at 11:12
  • @LPChip lol yes
    – Sharky
    Jul 4, 2016 at 11:18
  • This answer is factually incorrect and should be deleted.
    – henrebotha
    Oct 16, 2018 at 15:52

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