Around the world, the use of new technologies has grown exponentially, transforming the way people communicate at a distance, now more often through digital platforms than through other traditional means. Alongside this technological advance, there has been a worrying decline in citizen participation in interactions with governments, reflected in rising abstention rates, including in local elections, traditionally the closest level of governance to the citizen. Faced with this scenario, governments recognize the need to get closer to the population, and one of the strategies to achieve this is to incorporate new digital tools into communication with citizens, who are constantly present and active in these spaces. The digital communication channel most used by municipalities is the official website of each town hall. This study analyzes the content of the citizen participation functionalities made available through this medium, covering the 30 municipalities that make up the Portuguese archipelagos. The archipelagos of the Azores and Madeira are more exposed to natural disasters than the mainland due to significant floods such as the one that occurred in Madeira in 2010 and the recurrent seismic activity associated with the Azorean Triple Junction, so digital communication channels play an important role in managing these problems. The citizen participation policies available on the analyzed websites are presented throughout the study. In order to understand the asymmetries in digital citizen participation tools, a geographical exploratory analysis was carried out, with the construction of an e-participation index based on the functionalities of the websites, consisting of five indicators: the possibility to send suggestions, complaints, and denunciations; to make online requests for garbage collection and street cleaning; to vote online on public policies; to respond to satisfaction surveys; and to share events witnessed by citizens, from natural disasters to road accidents. The results show that the archipelago of Madeira has a more advanced level of e-participation than the Azores. Among the nine islands of the Azores archipelago, the eastern group has the highest level of e-participation (54%), as opposed to the central group (33%). A correlation table and a cluster analysis were carried out between the e-participation index and the determinants identified in the literature to understand the factors behind these asymmetries. It was found that a higher level of e-participation is associated with a lower number of mayoral terms, a smaller margin of victory in municipal elections, and the fact that the mayor is a woman. This study offers an expanded perspective on the functionalities that local council websites can incorporate while presenting the first detailed portrait of e-participation in the Portuguese archipelagos. It also explores the impact of certain factors on promoting online citizen participation, thus contributing to a deeper understanding of the dynamics of e-participation in specific regional contexts.