The Washington University Libraries have a trial subscription to the database Ethnologue: Languages of the World.
The most authoritative resource on world languages, Ethnologue catalogues all of the world’s known living languages. It features profiles of over 7,000 world languages, with alternate names, dialects, numbers of speakers, multilingualism, and other demographic and sociolinguistic information, if known.
Users can also browse maps and country digests. The University Libraries’ trial subscription runs through May 1, 2021.