In an electrochemical cell with electrolyte containing silver or copper salts, the metal deposition takes place on the surface of a transparent electrically conducting coating. Under certain conditions, the metal film becomes specular and the electrochemical cell periodically switches from transparent to mirror state in response to changes in the voltage. The data obtained on electrochemical cells switchable between transparent to mirror states are analyzed. It is noted that the electrolyte properties play the decisive role in characteristics of such devices. Their prototypes with three optical states: transparent‑transient semitransparent‑mirror are realized recently. The modes are achieved in which the mirror state is preserved for a long period (over 2 h) at switched-off voltage (deenergized state). These results allow us to expect that the development of electrochemically switchable glasses-mirrors for windows will soon reach its commercial stage.