Alkaline water electrolysis (AWE) stands as a well-established and promising route for sustainable hydrogen production. However, traditional AWE cells suffer from low performance and bulky size. Here, we introduce the integrated design, a streamlined architecture that maximizes space utilization and enhances inter-component contact. This geometric innovation requires only minor modifications in the manufacturing process to effectively double the gas production capacity without increasing the volume of the device across a wide voltage range. Utilizing Ni foam electrodes, the device achieves a 205 mA cm−3 output at 2.0 V. Through visual inspections and simulations, we compared the new and traditional designs, attributing performance improvements to optimized local electric fields. These findings not only demonstrate the feasibility of spatial engineering, but also illuminate a promising path to advance alkaline water electrolyzer technology.