Throughout history, the amount of data and information has increased with the arrival of new eras and the development of technology, leading to a rise in the number of available pieces of information. Thus, the need arises for a different type of journalism that allows journalists the space to share processed data. Data journalism is based on the collection, processing, and presentation of data. An important aspect of this branch of journalism is the way in which data is presented to the audience. Data can be presented to the public using tables, charts, illustrations, photographs, and videos. Data journalism provides journalists with greater freedom in reporting on topics that require the presentation of large amounts of data. This approach to journalism requires journalists to develop skills in creating interactive charts and tables. The purpose of this thesis is to present what data journalism is and the purpose of data visualization in data journalism. The theoretical framework will be presented using specific examples. In this paper, the method of content analysis was applied to three portals: The New York Times, The Guardian, and Politico.eu. The purpose of the content analysis is to determine how large amounts of data are presented on the selected portals and to show the application of data journalism in the modern world and portals.