Semantic Scholar

Semantic Scholar is a free academic search engine from the Allen Institute for AI, indexing more than 200 million papers across every discipline. Rather than keyword matching alone, it extracts meaning from full texts to surface influential citations, generate one-sentence TLDR summaries, and build personalised research feeds. Its open API and datasets also underpin a large number of other research tools, including several in this category. Two things worth knowing. Because it is run by a non-profit research institute rather than a subscription business, there is no paid tier, no usage meter and no upsell, which makes it a sensible default starting point before evaluating anything paid. And its infrastructure role means that when other tools advertise a corpus of hundreds of millions of papers, they are frequently building on data that Semantic Scholar makes openly available.