There currently are a variety of options to travel by night train from Mannheim to Mainz, taking between approximately 1 and 2 hours: Namely the ICE 618, the NJ 424, the NJ 402, the NJ 40468, and the IC 60402. These lines are operated by DB, and ÖBB.
Deutsche Bahn (DB) exited the actual night train business in 2016. However, it operates around a dozen Intercity and Eurocity trains that run exclusively at night. These trains only have first and second class seats. The cars remain lit throughout the night and the seats cannot be reclined.
The Austrian Federal Railways (ÖBB) operate the Nightjet and Euronight trains (the latter together with other national railway agencies). ÖBB night trains typically feature three types of carriages: seats, couchettes, and sleepers. While seats are only for the bravest, couchettes and sleepers offer a more comfortable journey. Couchettes accommodate up to six people, while sleepers are private compartments for one to three people. They sometimes include a private bathroom or even a shower, sometimes only a sink.
For the next 7 dates with connections, the cheapest offer starts at 18 EUR. Check our connection pages below for all availabilities!