Otter Potter

Cite Check

AI answers invent sources that look real. Select a reference list or any text with citations, right-click, and Cite Check tells you which sources exist, which are made up, and which have the wrong details.

Free for 20 citations a day. Pro is $29 a year.

A draft with its reference list selected, and the Cite Check panel listing each source: two verified, two not found, and one where the DOI belongs to a different paper.
Select the references, right-click, and see which ones are real.

What it checks

  • References in any styleAPA, MLA, Chicago, IEEE, Vancouver, and the bullet lists AI answers write. Each is matched by title, year and first author against Crossref, OpenAlex and Open Library.
  • IdentifiersDOIs, arXiv and PubMed IDs, and ISBNs are looked up directly.
  • Real IDs on the wrong sourceA common AI mistake: a real DOI attached to a different paper. Cite Check compares the record with what the text claims and shows what differs.
  • US court casesWith Pro and a free CourtListener token, case citations like 410 U.S. 113 are checked against the case-law database.
  • LinksOptionally confirms that cited links still load.
  • Honest resultsIf a database can't be reached, it says "Can't check", never "Not found".
Cite Check showing problems first: two references not found in any database, and a real DOI that belongs to a different paper than the one cited.
Problems first: invented sources and a DOI on the wrong paper.

Price

Free$0 Pro$29 a year
Papers, DOIs, arXiv, PubMed, books, linksYesYes
Citations checked20 a dayUnlimited
US court casesNoYes
Copy reportYesYes
CSV exportNoYes

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Questions

Does "Verified" mean the source supports the claim?
No. Cite Check confirms that a source exists and that its title, year and authors match the record. Whether it says what it's cited for still needs a human reading it.
What does "Not found" mean?
No record in Crossref, OpenAlex or Open Library matches the title, year and author. Most often the source was invented. It can also be something those databases don't cover, such as a local report, so treat it as "find this before you rely on it".
How accurate is it?
On a held-out test set of 10 real and 10 invented references, it caught all 10 invented ones and confirmed 9 of the 10 real ones before tuning. The repository's accuracy notes list every test case.
What leaves my browser?
Only the citations themselves, sent to the public databases. No account, no analytics, no server of ours. See the privacy policy.
Something else?
Email support@otterpotter.org.