To promote effective disaster countermeasures against possible tsunamis in the future, an effective appli-cation of tsunami hazard information is important. However, there were insufficient systems available for utilizing and applying various tsunami hazard infor-mation. Based on this situation, we developed and have been improving the Japan Tsunami Hazard In-formation Station (J-THIS), an open Web system available as a public portal for providing tsunami haz-ard information based on the probabilistic tsunami hazard assessment (PTHA). It provides tsunami haz-ard information through the following services: map services, data download services, and Web application programming interface (API) services. Based on the PTHA along the Nankai Trough, the J-THIS provides distributions of exceedance probability of tsunami heights for 30 years, tsunami hazard curves, earth-quake fault models, tsunami heights for each earth-quake fault model, and bathymetric charts. To illus-trate the use of the J-THIS, understanding how exist-ing coastal structures will protect us against tsunamis while enabling the local governments to set investment priorities in disaster risk reduction and resilience is key.