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Free reference checker for retracted and hallucinated citations.

Paste your reference list and this citation checker looks up every entry: retracted papers, DOIs that point to a different paper, and references no registry can find, the usual sign of an AI-invented citation. Every result names its source and keeps an explicit unchecked state.

0 / 60,000 chars

What can you paste?

For the strongest coverage, paste one DOI per line or export BibTeX or RIS from your reference manager. Plain-text lists are supported, but incomplete parsing stays visibly unchecked.

Inputs
DOIs, BibTeX, RIS, plain text
Run limit
Up to 200 references or 60,000 characters
Model use
No language model in the verdict path
Cost
Free, no account required
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Inspect the method

Interpretation

What does each result mean?

A missing lookup, a contradictory DOI, and a formal retraction are different facts. They stay separate in the result so a coverage failure never becomes a confident claim about an author.

01

Post-publication notice

A retraction, expression of concern, correction, or reinstatement record was found in Crossref metadata or the Retraction Watch dataset.

02

DOI-title mismatch

A DOI resolves, but it belongs to another work: its registered title does not match the structured title in a BibTeX or RIS entry, the two titles name different identifiers and none of the record's authors is cited, or the DOI opens a related paper while the cited paper is on record under another DOI. A plain-text title that only differs does not raise it.

03

No record found

Crossref, the DOI Foundation registration service, and a guarded title search all returned real negatives. This still requires manual verification.

04

Not checked

The reference lacked enough metadata, the source was unavailable, or coverage was inconclusive. This is not evidence that the reference is wrong.

Sources and data handling

Where does it look, and what does it keep?

Evidence sources

  • Crossref REST API: DOI metadata, bibliographic search, and deposited post-publication relationships.
  • Retraction Watch Database: retractions plus selected expressions of concern and corrections. Retraction Watch updates its source each working day; Manusights refreshes its DOI-keyed mirror weekly.
  • DOI Foundation resolver: independent registration-agency lookup before a missing Crossref record is treated as an absent DOI registration.
  • Hijacked Journal Checker: known clone domains. The tool does not infer a hijacked venue from a copied journal name or ISSN.

Read the complete pipeline and refusal rules.

What is retained

  • The submitted bibliography is processed server-side. The computed result, including parsed reference text, may be cached for up to 24 hours to avoid repeated external lookups.
  • Saved runs retain DOI and format fields plus sanitized findings. The exact pasted reference strings are removed before database persistence.
  • Operational notifications contain counts and result categories, never an input preview.
  • Share pages use unguessable tokens and carry a noindex directive. Copying a share link is the action that discloses that result to another person.
  • Submitted text is not used to train a language model.
Method reviewedSeptember 22, 2026
Evidence reviewRefresh every 90 days
Correction patherik@manusights.com

Limits

What can a reference checker miss?

  1. 01No flags found means no tracked issue was found in the sources checked at that time. It is not a quality endorsement.
  2. 02Retraction Watch is designed to be comprehensive for retractions, but its expressions of concern and corrections are not comprehensive.
  3. 03DOI-less references depend on a strict Crossref title search. Books, theses, proceedings, older work, and non-English material may remain unchecked.
  4. 04Plain-text parsing can split or merge references. BibTeX, RIS, or one DOI per line gives the strongest input.
  5. 05A known hijacked-journal clone is flagged only when the pasted reference includes a listed clone domain. Journal names and ISSNs alone are not enough.
  6. 06The checker does not determine whether a cited paper supports a claim, whether a study is sound, or whether a journal is suitable.

FAQ

Reference checker questions

Is the Manusights Reference Checker free?
Yes. No account or payment is required. The browser interface allows five runs per day, and each run accepts up to 200 references or 60,000 characters.
Can the Reference Checker find hallucinated or AI-invented citations?
It flags the pattern they leave. A reference is reported as No record found only when Crossref, the DOI Foundation registration service, and a guarded title search all return real negatives. That is how a citation invented by an AI writing assistant usually shows up. An unfound reference can also be a book, a thesis, or older work the registries do not cover, so the result asks for a manual check and does not call a reference fabricated.
Is this a citation checker for APA or other reference styles?
It checks the citations themselves, not their style: whether each reference exists, whether its DOI points to the paper you meant, and whether the work has been retracted or corrected. It does not check APA, MLA, or other formatting.
What does the Reference Checker verify?
It resolves DOI metadata, screens documented post-publication notices, compares a structured BibTeX or RIS title with the DOI record, checks the DOI registration agency when Crossref has no record, and flags an exact known hijacked-journal clone domain when that domain appears in the pasted reference.
What data sources does the Reference Checker use?
Crossref supplies DOI metadata, bibliographic search, and deposited post-publication relationships. Retraction Watch supplies a curated retraction dataset and selected related notices. The DOI Foundation registration-agency service guards non-Crossref DOIs. The Retraction Watch Hijacked Journal Checker supplies known clone-domain evidence.
How fresh is the retraction data?
Retraction Watch states that its production dataset is updated each working day. The Manusights mirror is scheduled weekly, while Crossref metadata is queried during the run and cached for up to 24 hours. A very recent notice can therefore be absent, and the checker never claims real-time completeness.
What does each verdict mean?
A retraction, expression of concern, or correction reflects a linked notice in the checked sources. A DOI-title mismatch means structured citation metadata disagrees with the registered title. No record found requires three real negative checks and still requires manual verification. Not checked means the evidence was missing or unavailable. No flags found is not a quality endorsement.
Is my bibliography stored?
The submitted text is processed server-side, and a computed result containing parsed reference text may be cached for up to 24 hours. Exact pasted reference strings are removed before saved-run database persistence. Operational email excludes input previews. Submitted text is not used to train a language model.
Can I cite the Reference Checker?
Yes, when describing a run of the tool. Cite the underlying Crossref, Retraction Watch, DOI Foundation, or Hijacked Journal Checker record directly when a claim depends on that provider evidence. The provenance page provides a bounded citation format.

Open research package

How often do papers cite retracted work?

The Retracted Citation Study reports a bounded 12,402-paper analysis with a research brief, CSV, JSON metadata, data dictionary, citation file, method, and limitations.

Open the research package

Timing question

Was the cited work already retracted?

The cited-after-retraction guide explains the timing question a current-status check cannot answer: was the work already retracted when it was cited, and where is the open data to measure it.

Read how the timing is measured