Hrvatska Internetska Enciklopedija (HIE) is an online reference resource offering a broad collection of articles across subjects including Croatian studies, geography, history, health and medicine, arts, science, technology, and sport. Its homepage features daily historical events, births, deaths, holidays, name days, and selected articles, alongside topic and alphabetical indexes. HIE also provides dedicated sections for preschool children and students across different primary and secondary school levels, aiming to make quality content relevant to school curricula accessible to learners, parents, and educators. The organization welcomes cooperation with educational institutions.

Beyond its encyclopedia, HIE offers access to photographs, diagrams, illustrations, podcasts, and databases. Many visual materials are available for non-commercial use, while some uses, including commercial applications, require a special licence. Podcasts can be listened to online or later. HIE also connects organizations with specialists in digitizing recordings, books, and photographs; presenting and analyzing information; and managing information and knowledge. These services include support for creating wikis and knowledge bases.