High entropy alloys (HEAs) or complex concentrated alloys (CCAs) are a novel class of materials that offer superior functional and structural performance in many applications ranging from electrical motors to transformers. In this work, we use atom-probe tomography (APT) and aberration-corrected transmission electron microscopy (TEM) methods, including quantitative magnetic imaging to study the phase separation on the local variations of the magnetic behaviour of AlCo(Cr)FeNi and AlCoFeNi CCAs.