The Microplastic Compendium (MPC) serves as digital source of information and platform on different aspects of microplastic pollution. It targets various interest groups, both interested readers without scientific background and people with relevant scientific questions. Most importantly, users can find aggregated information on various aspects of this highly relevant environmental problem. Extensive information was gathered on the scope and consequences of microplastic pollution, as well as possible measures and solutions tackling the issue from a policy- and industry perspective. For early starts in the scientific field, the most relevant reviews are linked. Additionally, recommendations for suitable chemical-analytical workflows are included. The MPC does not claim to be complete. Content selection of reviews and recommendations are based on authors’ point of view on personal expert knowledge. The contents are therefore subjective. They are largely extracted from the theses by Fadi El Gareb, Jeannette Hansen and Lars Hildebrandt. Experts from Hereon, the Helmholtz Centre for Environmental Research (UFZ), the Alfred Wegener Institute (AWI) and the University of Plymouth have kindly contributed special articles. Special thanks to Hatef Takyar for the development and maintenance of the portal. The MPC has been developed in the context and is part of the Coastal Pollution Toolbox (URL: www.coastalpollutiontoolbox.org), a knowledge hub and digital working environment and tool set to study contaminant, nutrient and carbon dynamics in temperate and polar coastal zones. URL: www.microplastic-compendium.eu