Recently I’ve been interested in what packets do my browsers send and receive. I’ve used Fiddler and Wireshark (with Name Resolution) for analysis. I’ve been surprised how much networking goes on in the background without me being involved. Some websites that I’ve opened long ago keep sending me packets after hours of not using them.
What perplexed me the most is browser’s behavior on startup. Whenever I open browser (Google Chrome or Brave) there are huge amount of packets my browsers send and receive without me clicking even once – just a blank start up page.
There is always network traffic between me and the most recent website(s) that I’ve opened. For example, if before closing browser I’ve opened nytimes.com, then after closing browser (with new blank tab as active tab) and opening again (even the next day) I can see through Fiddler and Wireshark that browser connects to nytimes.com even though I did not open its tab. I did not produce any click, yet it already establishes connection with it for some reason. Sometimes it’s just one site – the most recent one, or bunch of sites – Brave usually connects to one the most recent one, while Chrome might connect to bunch of the most recent sites. It seems stupid to me.
What’s more, sometimes my browser connects to websites that I haven’t opened for weeks (and it does it almost every time). For example for some reason Brave almost always connects to imdb.com and receives huge amount of packets (usually it is comprised of images that I can see in Fiddler)
So whenever I open a browser there is a lot of traffic going on (especially when there is connection to imdb.com that sends me a lot of images). It might add up to 100mb just by launching browser. Obviously it greatly slows down the launch. Apart from browser updating itself, I don’t want it to connect to any website and receive any packets. When I open a browser I don’t want the browser to open or reload any tab until I do so.
So the question is what is going on here and more importantly – how do I disable this annoying background activity? I’ve been searching the web thoroughly, yet couldn’t find any decent answers.
