Bremen Hbf to Kiel Hbf train with Deutsche Bahn (ICE,RE)

Deutsche Bahn (DB) is Germany’s main train operator, running around 40,000 domestic and international services each day. Its fleet includes a variety of train types: high-speed ICE (Intercity Express) trains, reaching up to 300 km/h; IC (Intercity) and EC (EuroCity) trains for long-distance travel; and IRE (Interregio-Express), RE (Regional Express), and RB (Regionalbahn) services for regional and local connections. While bathrooms are standard on all trains, amenities such as onboard restaurants and free Wi-Fi are available only on certain train types and routes. DB offers a wide range of fares, including Super Saver, Saver, and Flexible tickets, along with discount cards like the BahnCard 25, 50, and 100. Additional options include single tickets, day tickets, and group tickets. Popular routes include Berlin–Munich, Hamburg–Frankfurt, Cologne–Stuttgart, Berlin–Dresden, and Hamburg–Cologne, as well as numerous regional services across Germany.

FlixTrain is a German railway company owned by FlixMobility, the parent company of FlixBus. Since 2018, it has connected major German cities such as Hamburg, Cologne, Stuttgart, Berlin, and Frankfurt, and also operates routes in Sweden, including Stockholm to Gothenburg. All FlixTrain services run on 100% renewable energy. Onboard facilities include air conditioning, toilets, USB ports, power outlets, generous legroom, and free Wi-Fi on most trains. Food and drinks are available, and every ticket guarantees a seat. Passengers can bring luggage free of charge, provided it fits in the racks. Popular German routes include Berlin–Hamburg, Frankfurt–Stuttgart, and Cologne–Hamburg, offering a sustainable and comfortable way to travel

Metronom Eisenbahngesellschaft mbH is a German railway company that has been connecting Northern Germany since 2003. Based in Uelzen, it focuses exclusively on passenger transport, operating services from Hamburg to Bremen, Lüneburg, Uelzen, Hanover, and Göttingen. The company also runs services under the brand Enno from Wolfsburg to Hanover and Hildesheim. Metronom is partly state-owned, with its trains, which can reach speeds of up to 160 km/h, being rented from the state transport company Landesnahverkehrsgesellschaft Niedersachsen mbH (LNVG). They are known for their yellow and blue double-decker trains, offering amenities like extra legroom and refreshments.