Rubrics play a crucial role in shaping educational assessment, providing clear criteria for both teaching and learning. The advent of online rubric platforms has the potential to significantly enhance the effectiveness of rubrics in educational contexts, offering innovative features for assessment and feedback through the creation of erubrics. This study presents a comprehensive analysis of 19 online rubric platforms structured around five research questions (RQs) examining the general platform features, rubric design features, rubric implementation features, identifying the stronger online rubric platforms available, and investigating if the platforms support the creation and implementation of erubrics. Our analysis of the design features revealed varying levels of customisation and flexibility across platforms, crucial for effective assessment. Regarding implementation features, we found a mix of online and offline capabilities, with a limited number of platforms offering more advanced features (e.g. collaborative options). Through a detailed scoring system, we identify the platforms that lead innovation in design and implementation. Unfortunately, the vast majority of platforms do not support features for the creation of erubrics. We provide a detailed list of implementation recommendations for teachers, researchers, and platform designers (Appendix F).