Research Paper Search: DOI Metadata and Citations

Search more than 150 million scholarly works (journal articles, conference papers, books, chapters, preprints, reports and datasets) by topic, or look up any DOI. Each row gives you the title, authors, journal, publisher, publication date, abstract, citation count, reference count, subjects, ISSN, volume, issue and pages, license, funders and links to the full text.

The data comes from Crossref, the registry that issues DOIs for most of the world's publishers, through its open public API. There is no page scraping, no captcha and no blocking, so runs are steady. It is a practical alternative to Google Scholar scrapers when you need clean, structured metadata at volume.

What you can use it for

• Literature reviews: pull every journal article on a topic since 2024, with abstracts, ready for screening or an AI summary.
• Citation analysis: sort by most cited to find the key papers in a field, or look up the citation count of your own DOIs.
• Reference cleanup: turn a list of DOIs into complete, correctly formatted metadata.
• Research and grant intelligence: see which funders appear on recent papers in a field, and which journals publish the most on it.
• RAG and AI agents: feed abstracts and metadata into a knowledge base, or let an agent answer "find the 20 most cited papers on CRISPR off target effects since 2022".

Input

Field	What it does	Default
Search queries	Topics, one per line. Matched against titles, authors, journals and other bibliographic text	none
DOIs to look up	DOIs or DOI links, one per line	none
Published from / until	Date range, as 2024, 2024-06 or 2024-06-30	none
Work types	Journal article, conference paper, book chapter, book, preprint, report, dissertation, dataset and more	all
Sort by	Relevance, newest first or most cited first. Newest and most cited reorder the most relevant matches (five times the results you ask for, at least 200, at most 1,000) so results stay on topic	relevance
Only works with an abstract	Skip works without a deposited abstract	off
Only works with a license	Keep works that carry a license statement	off
Include abstracts	Turn off for smaller rows	on
Results per query	Up to 10,000	100
Your contact email	Optional. Crossref serves requests with a contact email from a faster pool. Sent only to Crossref, never saved	none
Maximum papers	Stop after this many rows in total	1,000

Example input:

{
  "queries": ["large language models in education"],
  "dois": ["10.1038/nature14539"],
  "fromDate": "2024",
  "types": ["journal-article"],
  "onlyWithAbstract": true,
  "sortBy": "relevance",
  "maxResultsPerQuery": 200
}

Output

One row per work. Download as JSON, CSV, Excel or HTML, or read it through the API.

{
  "query": "10.1038/nature14539",
  "source": "doi",
  "doi": "10.1038/nature14539",
  "doiUrl": "https://doi.org/10.1038/nature14539",
  "title": "Deep learning",
  "type": "journal-article",
  "journal": "Nature",
  "publisher": "Springer Science and Business Media LLC",
  "publishedDate": "2015-05-27",
  "year": 2015,
  "authors": ["Yann LeCun", "Yoshua Bengio", "Geoffrey Hinton"],
  "authorCount": 3,
  "abstract": null,
  "citationCount": 77191,
  "referenceCount": 103,
  "issn": ["0028-0836", "1476-4687"],
  "volume": "521",
  "issue": "7553",
  "pages": "436-444",
  "language": "en",
  "licenseUrls": ["https://www.springer.com/tdm"],
  "openLicense": false,
  "funders": [],
  "publisherUrl": "https://www.nature.com/articles/nature14539",
  "scrapedAt": "2026-09-27T06:57:07.221Z"
}

citationCount is the number of other Crossref works that cite this one. openLicense is true when the work carries a Creative Commons license. A DOI that does not exist is listed in RUN_SUMMARY in the run's key value store and costs nothing. The same paper is never saved twice in one run.

Pricing

Pay per event, no subscription, no charge for platform usage on top.

Event	Price
Paper saved	$0.001 (one dollar per 1,000 papers)

Examples: 200 papers on a topic cost $0.20. Looking up 1,000 DOIs costs $1.00. Set a maximum charge per run in Apify and the actor stops cleanly when it is reached.

Limits

• Abstracts exist only when the publisher deposited one with Crossref; many older and some large publishers do not. Use "Only works with an abstract" if you need them.
• Citation counts come from Crossref's own citation links. They are usually lower than Google Scholar's, which also counts web pages and theses.
• Without a contact email, Crossref's public pool allows about one request per second; each request returns up to 200 papers, so 10,000 papers take a few minutes. With a contact email it is faster.
• Relevance ranking is Crossref's. Results far down a very broad query get looser; narrow the query or add a date range and type filter.
• "Most cited first" and "newest first" rank the most relevant matches (up to 1,000), not every work in Crossref that shares a word with the query. This is deliberate: Crossref's own citation sort ignores relevance and returns off topic papers.
• Full text is not downloaded. The actor returns links; access depends on the publisher and the license.
• Google Scholar is not used or scraped.

FAQ

Do I need an API key or an account? No. Crossref's REST API is public and free. The optional contact email only speeds things up.

Is this the same as Google Scholar? No. It covers works registered with a DOI, which is nearly all journal and conference literature, many books and a growing share of preprints. It does not cover random PDFs on the web.

Can I search by author? Put the author's name in the query; bibliographic search matches author names too. The actor does not build profiles of people; author names appear only as the paper's published byline.

How fresh is it? Live. Crossref indexes new DOIs within hours of registration.

Is this affiliated with Crossref? No. It is an independent tool that reads Crossref's public API.