Nanoelectrode arrays have been widely used in electroanalytical applications. The challenge is to develop low-cost and simple approaches to the fabrication of superuniform and ultrasmall nanoelectrode arrays for improving analytical performance and imaging resolution. Here, superuniform and high-density gold nanoelectrode arrays with tunable electrode diameters and interelectrode distances have been fabricated by electrodeposition, followed by a simple mechanical polishing process. The fabricated free-standing arrays have a high density (108 cm-2) of nanoelectrodes (60, 140, and 200 nm in diameter), and can be used as closed bipolar electrode arrays to image electrochemical heterogeneity with micrometer spatial resolution. With the help of a confocal microscope, individual nanoelectrodes can be visualized and resolved from the reflected light. Thus, the nanoelectrode arrays are promising in electrochemical imaging with high spatial resolution.