A 95?mm x 40?mm x 15?mm compact reactor for hydrogen production from methanol-steam reforming (MSR) is constructed by integrating a vaporizer, reformer, and combustor into a single unit. CuO/ZnO/Al2O3 is used as the catalyst for the MSR while the required heat is provided using Platinum (Pt) -catalytic methanol combustion. The reactor performance is measured using three reformer designs: patterned micro-channel; inserted catalyst layer placed in a single plain channel; and catalyst coated directly on the bottom wall of single plain channel. Because of longer reactant residence time and more effective heat transfer, slightly higher methanol conversion can be obtained from the reformer with patterned microchannels. The experimental results show that there is no significant reactor performance difference in methanol conversion, hydrogen (H2) production rate, and carbon monoxide (CO) composition among these three reformer designs. These results indicated that the flow and heat transfer may not play important roles in compact size reactors. The reformer design with inserted catalyst layer provides convenience in replacing the aged catalyst, which may be attractive in practical applications compared with the conventional packed bed and wall-coated reformers. Copyright (c) 2011 John Wiley & Sons, Ltd.