Semantic Scholar

Semantic Scholar is a free search engine for academic research run by Ai2, the nonprofit Allen Institute for AI. Its about page, checked on October 24, 2026, says it provides free AI driven search and discovery tools and open resources for the research community, and that it indexes over 200 million academic papers drawn from publisher partnerships, data providers and web crawls.

The difference from a general search engine is that Semantic Scholar understands papers as papers. Its own models process and classify each paper, extract meaning and find connections between works, so you can understand a paper at a glance and move to related research by following citations and references. You can create a free account to save papers to a library and set up research feeds that suggest new papers on topics you follow.

Semantic Scholar is also a source for other tools. Ai2 publishes the Semantic Scholar Academic Graph dataset and APIs, which provide records for research papers across all fields, and the S2ORC corpus for text mining research. Several AI research assistants and reference tools build on this kind of open scholarly data.

Pricing: the about page describes the search and discovery tools as free, and we found no paid plan for individual readers.

Who it suits: students starting a literature search, researchers who want a fast free index with citation links, and developers who need scholarly data through an API. It is a sensible first stop before paying for anything. Who should look elsewhere: people who want a written answer to a question rather than a list of papers, where Consensus or Elicit summarize findings, and anyone researching everyday web topics, where Perplexity fits better. Because summaries and paper rankings come from models, read the full paper before you cite it, and check whether you can reach the full text through your library.