We report on the unusual electrochromic properties of Antimony-based Tin Oxide (ATO) powders or thin films grown by pulsed laser deposition (PLD). The cathodic coloration, linked to the nanocrystalline nature of the powders made by hydroxides co-precipitation, was investigated in the 0-70 at.% Sb range, and the best performance was obtained for antimony contents ranging from 20 to 40%. PLD ATO thin films were grown from targets with 30 and 40% Sb. The electrochemical and optical properties tiers found to be extremely sensitive io their morphology. Porous or cracked films could be colored, while dense ones presented a capacitive-like behavior and a neutral switching characteristic over a wide range of potentials. A successful attempt was made to assemble a chemically symmetric working device using the cracked or porous ATO coatings as the primary electrode, and the densest ones as the counter-electrode.