The 5th edition of the HPLC Phytoplankton Pigments Intercomparisons (HIP) Workshop takes place on 3-4 December 2024 in a hybrid format. This workshop focuses on the determination of Total Chlorophyll and other relevant phytoplankton pigments in natural waters. Organized by the Joint Research Centre (JRC), the event aims to present and discuss the results of the last HPLC phytoplankton pigment analysis and to plan future intercomparison activities. It provides a rich opportunity to create and expand a network of researchers focused on marine pigments analysis to support satellite data and bio-optical algorithm validation.