Works in both directions. Search by DOI to find the paper it points to and retrieve its full bibliographic metadata - or, if you have a citation but no identifier, search by title to find the paper’s DOI. Also accepts a PubMed ID, PMCID, arXiv ID, ISBN, ISSN, ADS bibcode, or paper URL.
7 identifier types · Title search across CrossRef, PubMed & OpenAlex · Free, no signup
We’ll resolve this identifier and show you the full bibliographic metadata. Nothing is stored.
Resolving an identifier confirms the paper exists - it does not confirm the citations in your bibliography point to the right papers. The dominant AI-fabrication pattern is a real, resolvable DOI paired with an invented title. Audit your whole reference list for fabricated citations before you submit.
Searching by a DOI such as 10.1234/jneurosci.2025.04123 finds the paper it points to and returns the full bibliographic record.
Nakamura, T.; Chen, L.; Okonkwo, A. B.; Rivera-Santos, M.
Journal: Journal of Neuroscience
Year: 2025
Volume: 45 (3)
Pages: 412–429
Type: journal-article
Source: CrossRef
Identifiers
10.1234/jneurosci.2025.0412339012345The other direction is often the harder one: a reference list gives you a title, some authors and a year, but no identifier, and you need the DOI. Switch the tool to I have a citation and it searches CrossRef, PubMed, and OpenAlex by title, merges records that appear in more than one registry, and scores each one against what you typed.
Every result is shown with its own title, authors, journal and year next to its DOI, plus a title-match percentage and the registries it came from. That is deliberate. A title search always returns something - so a finder that hands back a bare DOI and nothing else is inviting you to cite a paper you never checked. That is the same failure mode as a fabricated citation with a real, working DOI attached, which is exactly what the Citation Verifier exists to catch. When nothing scores well enough, the tool says so rather than guessing.
Enter the title on its own rather than pasting a full reference. The score compares your text against the record’s title, so authors, journal names and page numbers in the same field only dilute it. The author and year fields are there to narrow the search without that cost.
Not every work has a DOI. Books, chapters, and many pre-2000 articles were never assigned one, so a genuine paper can legitimately come back without an identifier.
A Digital Object Identifier (DOI) is a permanent link to a published work. Every modern journal article, preprint, data set, and increasingly every book chapter has one. A DOI always starts with 10. followed by a registrant code, a slash, and a suffix - for example, 10.1038/s41586-023-05881-4. Unlike URLs, DOIs never break: even if a publisher moves their website, the DOI always resolves to the current location of the work.
Searching by a DOI gives you the full bibliographic record - who wrote it, where it was published, when, and what identifiers it carries. This is useful when a colleague or a reference list has given you nothing but a DOI and you need to find out which paper it is, when you want to verify a paper’s details before citing it, or when you want to check whether a DOI is valid at all.
See the DOI entry in our glossary.
You can enter any scholarly identifier - not just DOIs. The tool resolves it against the appropriate database (CrossRef for DOIs, PubMed for PMIDs, arXiv for preprints, OpenLibrary for ISBNs, NASA ADS for bibcodes) and returns the full metadata. You can also paste a paper URL from a supported publisher site. If you’re not sure what type of identifier you have, try the Identifier Detector first.
The lookup returns all available bibliographic fields for the resolved publication:
Fields vary depending on the publication type and what metadata the source database provides. Books may include publisher and edition; preprints may lack volume and pages.
Paste the DOI into the field above and run the lookup. The DOI is searched against CrossRef (or the registry that issued it) and the full record comes back: title, authors, journal, year, volume, issue, and pages. You can also open the DOI directly at https://doi.org/followed by the DOI, which redirects to the publisher’s page - but that gives you the publisher’s landing page rather than structured metadata you can copy field by field.
Switch to I have a citation and enter the paper’s title, optionally with the first author’s surname and the year. We search CrossRef, PubMed, and OpenAlex, and show each matching record with its DOI, its own title and authors, a title-match percentage, and which registries returned it. Compare the title we show against the paper you want before using the DOI - a title search always returns something, and the closest record is not always the right one.
Enter the title on its own for the best results. The match score compares what you type against the record’s title, so authors, journal names, volumes and page numbers in the same field pull the score down and can hide the paper you are looking for. Put the first author’s surname and the year in their own fields instead. If the reference contains a DOI or PMID somewhere, the Identifier Detector will extract it and you can look that up directly.
The identifier may be malformed, or the upstream database may be temporarily unavailable. Check that you entered the identifier correctly - DOIs must start with 10., PMIDs are numeric, PMCIDs start with PMC. If the identifier is valid but the lookup fails, try again in a moment.
No - this tool shows you the raw metadata fields, not a formatted citation. If you want a citation in APA, Vancouver, or any other style, use the main Scholar Sidekick formatter.
Yes. No account required. Nothing you enter is stored.
Once you have verified the metadata, format the citation in any style, export to BibTeX or RIS, or check its retraction status and open access availability.
This page is a front end for the public Scholar Sidekick API — the same identifier lookup runs over plain HTTP, so you can call it from a script, an AI agent, or your reference manager. Light use needs no key at all. A free account issues an ssk_ key that raises your rate limit.