and Wanderu : Excellent for comparing train prices against bus and flight options in North America and Europe to ensure you're getting the absolute best deal.
: The official site for French rail travel. It is often the best place to find promotional fares for high-speed routes like Paris to Barcelona.
: The gold standard for German and cross-border European travel. Booking directly through their site often avoids extra transaction fees.
: Highly recommended for its "split ticketing" technology and a fee-free mobile app. It often finds the cheapest or joint-cheapest fares for long-distance journeys.