A summary of database comparisons, particularly focusing on Google Scholar and other large research databases. It deliberately focuses on content and search features rather than pricing as this varies for each subscribing institution.
Librarians have been actively examining overlap in research database coverage for many years in an attempt to provide the widest possible coverage of the published literature in the most fiscally responsible manner possible. As library budgets become more stretched by ever-increasing journal subscription costs and decreasing institutional budgets, database comparison articles become extremely useful in assisting with decisions on possible database cancellations/purchases.
In 2018, librarians at the University of Maryland were asked to justify purchase of agricultural databases given the free availability of Google Scholar. The result was the following article:
Given the likelihood that this same scenario may come into play in numerous other disciplines, this page is intended to be a summary of database comparisons...including a collection of links to database comparisons published within the last 5-7 years. It is not a comprehensive listing - - but it is hopefully as unbiased as possible, relying on research studies and vendor-supplied facts.
Based on results of a research study: Martín-Martín, A., Thelwall, M., Orduna-Malea, E., & Delgado López-Cózar, E. (2020). Google Scholar, Microsoft Academic, Scopus, Dimensions, Web of Science, and OpenCitations' COCI: a multidisciplinary comparison of coverage via citations. https://arxiv.org/abs/2004.14329