Micromixer is a significant component of microfluidics particularly in lab-on-chip applications so that there has been a growing need for design and fabrication of micromixers with a shorter length and higher efficiency. Despite most of the passive micromixers that suffer from long mixing path and complicated geometry to increase the efficiency, our novel design suggests a highly efficient micromixer while taking advantage of having a short length. The novelty of our work stems from utilizing all three mixing techniques of injection, recombination, and zigzag mixing resulting in benefits such as multi-flow lamination and flow resistance reduction in microscale. Moreover, the contraction and expansion of the microchannel width improve mixing. The present work deals with the parametric study, numerical simulation, as well as experimental tests and characterization of small planar passive micromixer. The high mixing efficiency yield of 98.02 was obtained with the length of only 1857.8 microns which shows good agreement in comparison with numerical simulation.