High magnetic fields are a powerful tool for revealing the secrets of quantum materials. These allow exploring the origin and nature of charge-carrier interactions, resolving molecular structures, unveiling the environments in which atoms and molecules are embedded into, or even discovering new states of matter that can be used in novel technological applications. In this colloquium I will present general aspects of some of the experimental tools for studying quantum materials using high magnetic fields. I will highlight examples showing how high magnetic fields have helped at characterizing and understanding new correlated electronic states emerging in the proximity of a quantum critical point in high temperature superconductors; and how high magnetic fields have helped at revealing exotic mechanisms that lead to superconductivity and high thermoelectric figures-of-merit in low carrier density semiconductors.