In recent years, the technology of waveguide-based planar solar concentrators has been getting more attention in the Concentrated Photovoltaics (CPV) sector due to its compact design and performance versatility and its extended potential applicability from large power plants to built environments, such as Building Integrated Photovoltaics (BIPV). Within the last two decades, geometric design-based Planar Light Concentrator (PLC) and diffraction grating-based PLC have been developed with versatile design architectures along with luminescent PLC, which relies primarily on the development of concerned luminescent optical materials. However, congregating and evaluating the technical advancement gained in the field seems challenging due to the segregated state-of-the-art approaches. Hence, this review attempted to organise the present state of waveguide-based PLC in the frame of reference of PLC optics and optical material design. A systematic comparison of optics and optical material design parameters and the merit of the different PLC systems have been explored within this review to serve as a ready reference for its adoption to develop compact planar waveguide-based CPV systems.