We will be traveling by train from Nurnburg, Germany to Strasbourg, France in December. I've read that you have to change trains depending on the route you choose, but is there a direct train?
The best connections require at least one change of train. In Stuttgart, that one change is between track 11 and 12 - tracks which share the same platform.
Thank you. Are you able to book a ticket for the whole trip (including the connection in Stuttgart) at the Nurnberg train station?
"Thank you. Are you able to book a ticket for the whole trip (including the connection in Stuttgart) at the Nurnberg train station?" Yes, but if you wait until December, you will pay the full fair. As early as 90 days prior, you can order the tickets online for a discount. The price generally increases the longer you wait.
You can't go from Nürnberg to Strasbourg without a change in Stuttgart. Big deal. Last month I flew from Denver to Oakland, CA, and had to go through Phoenix, not exactly online between Denver and Oakland (nowhere near). At least Stuttgart is inline with Nürnberg and Strasbourg. Changes of vehicles are a part of life.
If you have a smart phone download Deutsche Bahns app. Wonderful app for traveling in Europe. If you are going to the Christmas Market in Strasbourg, reserve your seat early as possible. My wife and I were using rail passes and had to wait an extra day because we waited to late to reserve a seat. Have fun
Eurolines operate a direct bus from Nürnberg (Nuremberg) to Straßburg (Strasbourg). http://www.eurolines.de/index.php?id=2&L=1
In all fairness, the bus runs (one time) every 2nd or 3rd day. There are trains with 1 change four times a day, trains with more changes several times an hour. The one change trains take 4½ hrs. The bus takes 4½ hrs until end of August; then is takes 6½ hrs. Most train connections, even those with multiple changes, take less than 6½ hrs. The full fare bus fare is a few Euro less than the full fare train fare. The bus matches the advance purchase, non-refundable train fare. One other thing, it doesn't look like the bus runs in December (at least not shown on website past October).