Question on Split Testing

I have a tube site but would like to perform a split test where if user goes to X site, they would either go to A (my site) or B (another site). I was wondering if there are any tools to scripts to do this? I have tried searching through the forum and Google and still cannot find what I need. Hopefully it's free or has a trial so I can make sure it works with my test. If anyone knows about any tools like this, would you kindly inform me, thanks! Sorry if this isn't the right place to do this.

There is a lot of tools for AB testing. If you are using Google Analytics you have Experiments in Behavior section. You can't go wrong with this - it's free and easy to set up.
optimizely.com is more easy to set up but its a paid service.