The Axion Dark Matter Experiment (ADMX) at the University of Washington uses a strong magnetic field to detect the possible weak conversion of axions to microwaves. ADMX searches the galactic dark matter halo for axions resonant with a cold microwave cavity. ADMX has excluded optimistic axion models in the 1.9–3.53 μeV range. From 2013 to 2018 a series of upgrades were done and it is taking new data, including at 4.9–6.2 μeV. In December 2021 it excluded the 3.3–4.2 μeV range for the KSVZ model.