1. A computer-implemented method of improving rendering performance of complex web pages with four or more iFrames, including: evaluating function libraries used within iFrames on a complex web page that includes four or more distinct iFrames to identify sets of identical redirectable function libraries that are referenced in multiple distinct instances within the distinct iFrames; and mapping redirection of each set of identical function libraries to a canonical function library, whereby loading the complex web page includes loading the canonical function library instead of loading the multiple distinct instances of the identical redirectable function libraries in the distinct iFrames.