We have proposed a new design for a micromixer that uses ridges along with aligned inlet channels, that is, a vortex T-mixer with ridges (VTR), to induce a vortex inside a microchannel. To evaluate its mixing performance, we compared this T-mixer to a simple vortex T-mixer (SVT) at different Reynolds numbers using both water and water-dye mixing species. Our results show that the proposed T-mixer with ridges generates fusing flows at low Reynolds numbers (Re > 20) when compared to the vortex T-mixer. The vortex, instigated at the inlet of the micromixing channel, initially enhances the interfacial area of the fluid streams in both mixers by folding and stretching. However, at higher Reynolds numbers, the mixer with ridges showed better mixing characteristics. The vortex mixer is convenient to design and actuate the generation of the vortex flow based on the Reynolds number.