Miniaturizing soft robots is often limited by scaling down actuators while keeping high energy density and good response time. In this work we demonstrate the wafer-level microfabrication of electrostatic zipping soft actuators, similar to peano-HASELs. This methodology allows scaling electrohydraulic actuators down to millimeter and sub-millimeter size for highly integrated soft milli-robots. Benefits for soft robotics include repeatability, high precision devices and lower actuation voltage. We demonstrate a miniaturized soft actuator which is part of a swimming milli-robot operating with voltages of 300 V instead of the typical 1–5 kV.