It also does not require you to type it, because the server wouldn't be sure that the number really belongs to you.

At this stage your browser is ready do the WhatsApp App work, but it does not know what is your ID (Whatsapp identifier which is your mobile number), because it can't really get you phone number from thin air. Ģ.3 - Notice that this specific WS that the server has open between the Server and the Browser is associated with the unique QR code !!! So, knowing the QR code, the server knows which WS is associated with it! This is sent by the Server to the Browser, throught the WebSocket (WS we call it from now onwards)Ģ.2- On each QR Code refresh received on the WS, your browser does a GET request for the new QR Code in BASE64 encode. 1- You open the following URL on your browser : Ģ- The Browser loads the page with all sorts of JS and CSS stuff, but also opens a WebSocket ( wss://w4./ws ) - Check this image :Ģ.1- Every 20000 milliseconds you see traffic on the WebSocket for a refresh on the QR code you have on you screen.

Wa web barcode