I'd like to perform a live demonstration where the same web page, created two different ways are loaded at the exact same time, side-by-side.

... the purpose of this is to demonstrate speed differences between various frameworks or approaches to building web pages. Instead of presenting benchmark results, I'd like to show what speed differences actually look and feel like.

I know that I can create a Chrome extension to do this, but I'm wondering if I'm overlooking some simple way to accomplish this without writing code?

**Note**: (in response to comments below) I already have the two web pages hosted at different URLs (for example `http://localhost:4400` and `http://localhost:4401`). This question is not about how to serve two pages, it's about how to load them simultaneously and side-by-side.