The traditional time to check the references
Check your references before the portal does.
This is naturally when we discover that one DOI opens the wrong paper, another appears twice, and the preprint may have grown into a publication.
Paste the list. The tool checks whether each DOI resolves and matches its Crossref record. It cannot tell whether the source supports your claim. Nothing is stored; only DOI and metadata queries go to Crossref.
DOI and metadata queries go to Crossref, nothing else leaves the browser, nothing is stored, no account, no telemetry.
What this checks
- Does the DOI resolve? Each DOI is looked up in Crossref. Found, or not found.
- Does the record match your citation? The Crossref title, first author, and year are compared against the citation text around the DOI.
- Retractions and corrections: flagged from Crossref update metadata, naming Crossref as the source.
- Preprint DOIs: labelled preprint, so you can check for a published version. A preprint is not a problem.
- Malformed DOIs and duplicates: a DOI that isn't well-formed, or the same DOI cited twice.
Every reference gets one of three verdicts: checks out (resolves and matches), does not check out (resolves but the record disagrees, or is flagged), or not resolvable (Crossref returned nothing, so there is nothing to compare). A missing record is never counted as a failure.