I will travel from Frankfurt to Berlin by ICE and I wanted to ask if there is Wi-Fi in the trains and how much does it cost?
It's available on most ICE routes, but not all.
Cost wise there it's 4,95€ a day in standard class, though there's a small number of roaming partners with whom you can get online in standard class too (mostly T-Mobile Germany though). It used to be paid-for in first class as well, but as of late 2014, it's now free for first class customers (matching what most other European high speed operators do for their wifi).
DB has a page in English that lists the current routes it's available on, and have a pdf map. (Note that the English language map and pages are older than the German ones!). I believe that as of 2015, most of the major routes should offer it. A (possibly incomplete) list of where it's available, as given on their website, is:
- Dortmund - Düsseldorf - Cologne (also via Hagen and Wuppertal)
- Cologne - Frankfurt (Main)
- Frankfurt (Main) - Stuttgart - Munich
- Frankfurt (Main) - Nuremberg - Munich
- Frankfurt (Main) - Hanover - Hamburg
- Frankfurt (Main) - Mannheim - Freiburg
- Dortmund - Hanover - Berlin
- Göttingen - Wolfsburg
- Berlin - Hamburg
- Fulda – Würzburg
Since 1 January 2017 there is Wi-Fi in all ICE-Trains. From DB-Homepage:
In first class we offer you worry-free internet access. With the internet provided in first class you can work efficiently and even send and receive large mail attachments. You can also watch videos or listen to music.
In second class you can use the internet for free, but your data volume is limited. We offer you a basic internet service in second class that allows you to network and communicate, send and receive e-mails, and stay up to date with Facebook, Twitter and the like.