NationMaster is a statistical website that aims to facilitate comparison of publicly available data on all countries of the world. Self-described as "a massive central data source," the developers bring together information found in a wide range of documents, including the Central Intelligence Agency World Fact Book and various United Nations reports and surveys. A wide range of demographic indicators are covered, including literacy rates, taxation levels, and murders per capita. These are also available in pie charts, scatterplots, and correlation graphs.

In Nationmaster, one can find relationships between variables contained within countries as well as a fully integrated encyclopedia with over one million articles.

NationMaster's database is composed of data that originated from sources in the public domain, including national censuses, the United Nations Development Programme, the UNESCO Institute of Statistics, the United Nations Conference on Trade and Development, the World Trade Organization, World Bank Development Indicators, the World Resources Institute, the World Health Organization, Organisation for Economic Co-operation and Development (UNCTAD) reports, the Central Intelligence Agency World Factbook. NationMaster also contains an incomplete mirror of the encyclopedia content from Wikipedia.