My Galaxy S4 not showing mobile websites - why?

I had a Galaxy S2 and when I viewed mobile websites such as craigslist the website showed up as a mobile website. I now have the Galaxy S4 and when going to craigslist it is showing just like on a desktop. I went into the browser settings andmade sure it is not set for desktop view. Even when I change this the site looks the same. Does anyone know why this is? Is it because the device has a higher resolution that it assumes you want to view like desktop websites?

Thanks,

Warren