The execution of web pages generally involves three tasks: fetching resources, page layout and rendering, and JavaScript execution. Apart from these, sometimes websites need to track user behaviors so they need many third party integrations and this may affect page load time. Also, we can have different problems like javascript, instability, etc. We can filter all these things using BroserMob Prox
![WebDriver and BrowserMob Proxy](https://cdn-ak-scissors.b.st-hatena.com/image/square/d27683a257c092ba6c6f6fb57aa536b54cebbea5/height=288;version=1;width=512/https%3A%2F%2F224926-685269-raikfcquaxqncofqfm.stackpathdns.com%2Fwp-content%2Fuploads%2F2016%2F04%2Fproxymob_logo.jpg)