Litmaps vs OpenAlex

Litmaps is a web-based research tool that uses citation networks and advanced search to help researchers find papers and conduct literature reviews. Its search catalogue contains more than 270 million papers. A Litmap visualizes connections among articles through citations and references; users can annotate papers and change how the map is arranged. Topic monitoring sends automatic emails when new articles appear, and maps can be shared as images, public links, or with selected email addresses. The free plan costs nothing and includes basic search, up to 20 inputs and 100 articles, one Litmap, and a monthly summary, but no collaboration. Pro (Education) costs $10 a month, billed $120 / year - save 20%; it adds advanced search, unlimited inputs, articles, and Litmaps, plus daily or configurable alerts, and requires an academic email address. Litmaps Pro syncs Zotero collections with Litmaps Tags in both directions. Articles can also be imported from BibTeX, RIS, or PubMed files and exported in BibTeX, RIS, or CSV formats. Open Access PDFs are available to all users; other PDF access requires institutional access through LibKey.

OpenAlex is a free and open catalog of scholarly research, with a REST API for querying connected records such as works, authors, sources, institutions, and topics. API users can search, filter, sort, group, page through results, select fields, and retrieve individual entities. The complete database snapshot can be downloaded from Amazon S3 without an AWS account, and the data is released under the CC0 public-domain license. An official command-line tool supports bulk downloads with parallel transfers, checkpoints, rate limiting, retries, and resume. Full-text access provides PDFs and machine-readable TEI XML; each file download costs $0.01. Website exports include CSV, RIS, and TXT, while VOSviewer connects through the API. OpenAlex also offers Unpaywall's legacy-format open-access API, including a browser extension and integrations with SFX, EBSCO Discovery Service, and 360 Link. Its coverage includes journal articles, conference papers, books, chapters, datasets, dissertations, and preprints. OpenAlex is operated by a US 501(c)(3) nonprofit, and its code is open source.