This is one of the biggest myths people think and a lot of consultancies exploit it by telling prospective students who want to study in Germany. You do not study for free in Germany. You might end up in a university where you do not have to pay fees for a course but you do not study for free. There are two different things:

1. Semester fees
2. Course fees (tuition fees)

Public universities in Germany (universities funded by the government) do not charge you course fees. The course is taught to you for free as the education is subsidized. However, there are always semester fees, known as semester Beitrag for any university you study. The latter may vary depending upon the state you are studying in but, usually varies somewhere from 250€ – 400€.

You can choose scholarships that take over all the costs of your studies, including the semester fees as well as the course fees such that you do not have to pay for anything from your pocket, but there is no running away from this fee, at least not yet (it is 2022!).