NodeJs and client side javascript

I am wondering if NodeJS allows one to run “client side” javascript on the server? This is just a random thought I had that if this is possible it may be possible to move some (or all) of the client side javascript to the server. This would enable me to fetch web pages, on the server side, and after running the javascript on the server, allow me to see exactly what would be presented to the end user. Am I barking up the wrong tree with this?