The article «Application of Google Trends web-analytic tools in socio-humanitarian and library studies» examines the problems of using web-statistical tools by foreign and domestic experts in the field of library and social sciences. The article is divided into five parts. The first one sets the objective and main tasks of the work, gives a general description of both Google services as a whole, and the chosen research method, discusses the history of its creation and implementation. The second part analyzes the appeal to this method by experts of the International Library Association, demonstrates this method at the IBA session in Kuala Lumpur in 2018. The third part demonstrates the method use in modern socio-humanitarian studies presented in the international full-text Springer Databases Link, Oxford University Press and Sage. The paper considers the works of German and Russian authors actively using this method in library studies. The fourth part describes the capabilities and limitations of the Google Trends toolkit compared to Yandex-Wordstat, its Russian counterpart. The fifth part presents the main conclusions and substantiates the significance of this method for sociological research, sets out prospects for the further use of the Google Trends service to solve current library problems.