Academic Paper Search – Google Scholar Alternative (Crossref API + Open-Access PDFs)

Search 150+ million research papers by keyword, author, journal or DOI and get clean, structured metadata: title, authors (with ORCID and affiliations), journal, year, volume/pages, abstract, citation count, subjects, funders, plus a legal free PDF link when one exists (Unpaywall) and ready-made APA and BibTeX citations.

It uses the official Crossref REST API and Unpaywall, so there is no Google Scholar blocking, no CAPTCHA and no proxy. $1 per 1,000 papers. Not-found DOIs and filtered papers are free.

What it does

• Keyword search across journal articles, conference papers, preprints, books, chapters, dissertations, reports and datasets.
• Sort by relevance, most cited, newest or oldest. "Most cited" keeps only works whose title or abstract contains every query word, so famous papers rise to the top instead of loosely related ones.
• Author search (author), alone or combined with keywords; every listed author name must match. Journal / conference filter (journal).
• DOI lookup in bulk (10.1038/..., https://doi.org/... and doi: prefixes are accepted).
• Filters: year range, work type, minimum citations, only papers with an abstract, only open access.
• Open access (Unpaywall): isOpenAccess, oaStatus (gold, green, hybrid, bronze), a direct free PDF link, landing page, version and license.
• Citations: APA 7 string and a BibTeX entry for every paper.
• Alerts: onlyNew + sort newest on a schedule returns only papers you have not seen before.
• Optional OpenAlex enrichment with your free OpenAlex key: topics, keywords, author institutions and countries, FWCI and the OpenAlex citation count.

Use cases

• Literature reviews and systematic reviews: export every paper on a topic with abstracts and DOIs to a spreadsheet or reference manager (BibTeX).
• Research monitoring: weekly alerts for new papers in your field or by specific authors.
• AI and RAG pipelines: feed abstracts and open-access PDF links to LLMs.
• Bibliometrics: citation counts, journals, funders and publication trends.
• Sales and recruiting in science: find active researchers by topic, with ORCID and affiliations.

Input example

{
  "queries": ["large language models"],
  "sort": "mostCited",
  "yearFrom": 2023,
  "maxResultsPerQuery": 50,
  "includeOpenAccess": true
}

Author alert:

{ "author": "Geoffrey Hinton", "sort": "newest", "maxResultsPerQuery": 20, "onlyNew": true }

Output example

{
  "doi": "10.1038/nature12373",
  "title": "Nanometre-scale thermometry in a living cell",
  "authors": ["G. Kucsko", "P. C. Maurer", "N. Y. Yao", "..."], "firstAuthor": "G. Kucsko",
  "journal": "Nature", "publisher": "Springer Science and Business Media LLC", "type": "journal-article",
  "publishedDate": "2013-07-31", "year": 2013, "volume": "500", "issue": "7460", "pages": "54-58",
  "citationCount": 1849,
  "isOpenAccess": true, "oaStatus": "bronze",
  "oaPdfUrl": "https://www.nature.com/articles/nature12373.pdf",
  "citationApa": "Kucsko, G., Maurer, P. C., … (2013). Nanometre-scale thermometry in a living cell. Nature, 500(7460), 54-58. https://doi.org/10.1038/nature12373",
  "doiUrl": "https://doi.org/10.1038/nature12373"
}

Pricing (pay per event)

Event	Price
Paper (metadata + open-access lookup + citations)	$0.001
Actor start	$0.00005

Invalid or not-found DOIs, filtered papers and onlyNew repeats are free. Set a maximum cost per run and the Actor stops cleanly at that limit.

Actor	Price
This Actor	$0.001 per paper
themineworks/academic-research-mcp	$0.0625 per search call

Competitor price from the Apify Store on 2026-10-18.

FAQ

Is this the same as Google Scholar? No. It searches Crossref, the DOI registry used by almost all journals, publishers and many preprint servers. It has no Google Scholar data and does not access Google. Citation counts are Crossref's (citations between Crossref-registered works), which are usually lower than Google Scholar's.

Why do some papers have no abstract? Abstracts are included when the publisher deposits them with Crossref, which covers a large share of recent papers but not all.

Are the PDF links legal? Yes. Unpaywall only lists free copies hosted by publishers or repositories.

DOIs that are "not found"? DOIs from DataCite (datasets, Zenodo, some repositories) are not in Crossref. They are returned free.

Data sources

Crossref REST API (metadata is free to reuse), Unpaywall (open-access locations), and optionally OpenAlex (CC0). Not affiliated with Crossref, Unpaywall, OpenAlex or Google.

Use with AI agents (Apify MCP)

Works as a tool in the Apify MCP server: "Find the 20 most cited papers on retrieval-augmented generation since 2023 with free PDFs."