Novel ionogels encompassing an ionic liquid encaged in an inorganic matrix were synthesized by sol-gel chemistry. The ability of these highly conducting ionogels (∼10-2 S cm-1 at 25 °C) to act as liquid electrolytes in spite of their solid form has been exploited in inorganic electrochromic devices based on tungsten oxide and Prussian blue electrodes. These devices exhibit extremely fast switching kinetics and make it the best and only candidate for the realization of fast all solid state electrochromic devices. © 2007 Elsevier B.V. All rights reserved.