Scalable Way Of Executing With DOM Objects Embedded In HTML?

I'm trying to figure out if there's an easy way to execute all the Javascript code included or referenced in an HTML document even if given code references DOM objects.I basically have some Javascript code that makes a POST to my server. The POST payload includes a unique identifier for that html page, so I know if the JS was successfully executed if I see the unique identifier in my server's logs.

At first I wanted to test if the javascript in 5 pages worked, so I manually opened the 5 sites and verified my logs. I then wanted to see if the JS in 100 pages worked, so I wrote a little script that launches 100 tabs in FF staggered (I also used a nifty tool -- autocomplete, to close old tabs). I then wrote a utility to go through my server's logs and verify that the 100 unique identifiers that I was expecting were there... So this also worked fine!But now I want to move forward and test 1K or maybe even 10K sites. Is there anything I can use to execute Javascript embedded in an html page? Hopefully asynchronously?