I want to see what scripts web pages load into memory because sometimes they are malicious and I do not see what content or process is triggered.
More than CSS, IMG, Media, Font....etc
In Firefox browser, you can open debugger,set a breakpoint, inspect elements... by Firefox Developer Tools. Read more in that link
In opera browser, Opera Dragonfly — our fully-featured suite of developer tools, designed to make your job easier. It’s just a right-click away. No install required.Futher more you can search opera dragonfly