QED tests in magnetic fields

Magnetic fields are a very well known probe to investigate matter properties I will present how magnetic fields can also be used to test QED predictions in vacuum and in bound systems After a general overview of the field I will concentrate myself on the experimental effort that we are pushing forward at the High Magnetic Field National Laboratory in Toulouse France to measure for the first time the vacuum magnetic birefringence and the g factor of the electron in bound states at a level of interest for QED I will show our last results in both activities