The paper proposes the realization and the preliminary characterization of a short–range localization systems based on the measurement of magnetic fields. Fixed anchors that generate sinusoidal wave magnetic fields at different frequencies and mobile anchors that measure the received magnetic field values compose the system. Main topics faced in the paper are: the realization and the preliminary characterization of threedimensional magnetic field sensors based on the suitable arrangement of single axis TMR magnetic sensors and the proposal of a novel, scalable and flexible localization set-up allowing multiple mobile agents without increasing the complexity and the operational time of the system. Thanks to the low cost and the flexibility of the proposal, the realized system has a wide impact on the possible applications in industrial, medical and smart-life fields. For example, it can be adopted in localization of probes that execute the defect detection in specimen, in the realization of low cost devices that help in recognizing the health–state of peoples affected by motor problems related to neurological diseases, in application related to the virtual reality, etc. At this stage, the obtained results place the measurement accuracy lower than 1 cm when the localization range is a cube of 30 cm.