Have an old(er) ASP.NET project where javascript files put all their functions and variables in the global namespace? Want to move to modern javascript (ES2015) with dynamic module loading? If you don’t know where to begin, this guide might be able to help you. I was facing the same issue in an ASP.NET project (MVC, but it should be possible for WebForms too). It’s actually quite simple. We’ll go from this: Browser loads a page Browser loads all included javascript