Amorphous brazing foils are increasingly used on a wide variety of component geometries because of their flexibility and the resulting ease of application. Due to the recent rapid rise in Ni prices, there is an enormous need for research into the substitution of nickel with iron within conventionally used nickel‐based amorphous brazing foils. To avoid time‐consuming series of experiments, newly developed thermodynamic databases will be used to predict alloy compositions with a high glass forming ability. Foils should be produced with the melt‐spin process and characterized with differential scanning calorimetry and secondary electron microscopy. Novel iron‐based brazing foils with different compositions are successfully produced in the alloying system iron–nickel–chromium–silicon–boron. The characterization of these foils indicates the presence of a partly amorphous or nanocrystalline structure. The novel iron‐based brazing foils are characterized by a simple and cost‐efficient alloying concept. Furthermore, newly developed thermodynamic databases in the iron–nickel–chromium–silicon–boron system are validated by the successful production of these foils. The prediction of further iron‐based amorphous foils with the aid of thermodynamic calculations can thus be made possible.