Stretchable and wearable WO3 electrochromic devices on silver nanowire (AgNW) elastic conductors are reported. The stretchable devices are mechanically robust and can be stretched, twisted, folded, and crumpled without performance failure. Fast coloration (1 s) and bleaching (4 s) time and good cyclic stability (81% retention after 100 cycles) were achieved at relaxed state. Proper functioning at stretched state (50% strain) was also demonstrated. The electrochromic devices were successfully implanted onto textile substrates for potential wearable applications. As most existing electrochromic devices are based on rigid technologies, the innovative devices in their soft form hold the promise for next-generation electronics such as stretchable, wearable, and implantable display applications.