Advanced monitoring services capture browser interactions with websites using macro recorders, or browser add-ons such as Selenium or iMacros. These services test a website by running a web browser through a typical website transaction (such as a shopping cart) or a custom scenario, in order to check for user experience issues, performance problems, and availability errors. Browser-driven monitoring services detect not only network and server issues, but also webpage object issues (such as slow loading JavaScript, or third-party hosted page elements).