Crossref Simple Text Query

<p>Crossref Simple Text Query is a free web-based matching tool at <a href='https://doi.crossref.org/simpleTextQuery' target='_blank' rel='noopener'>doi.crossref.org/simpleTextQuery</a> that takes an unstructured reference or reference list — pasted as plain citation text, not structured fields — and returns the matching DOI for each item it can identify. A submission can hold up to 1,000 references, entered one per line or block, and the tool attempts to return exactly one best-match DOI per reference by default (an option to list all possible matches is available when a reference is ambiguous). No Crossref membership or account is required to use it, and there is no charge. The same underlying free-text matching is also exposed programmatically through the Crossref REST API's <code>query.bibliographic</code> parameter on the <code>/works</code> route (for example <code>api.crossref.org/works?query.bibliographic=your+citation+string</code>), which is the machine-actionable equivalent of pasting a citation into the web form — useful for batch reference-linking pipelines rather than one-off lookups.</p>

ByCASRAI Editorial Board

· Last updated 18 Jul 2026

Worked examples

Is an instance

A librarian has a scanned bibliography with no DOIs and pastes 40 loosely formatted references into the Simple Text Query form to get a DOI for each, rather than searching for each citation one at a time.

Is an instance

A publisher's production system calls the Crossref REST API with query.bibliographic=<full reference string> for every entry in a manuscript's reference list, as an automated step in building a linked reference list before deposit.

Is an instance

A researcher has only an in-text citation copied from an old PDF (author, year, partial title, no DOI) and uses Simple Text Query to recover the DOI needed to link it correctly.

Looks similar, but isn't

Not an instance

Looking up a DOI when you already have it, or resolving doi.org/10.xxxx/xxxx to its landing page — that is DOI resolution, not text matching, and needs no query tool.

Not an instance

Depositing new metadata for content a publisher owns, which uses Crossref deposit XML submission, not Simple Text Query (Simple Text Query only searches existing registered metadata, it does not register anything).

Crossref Simple Text Query solves a specific, common problem: you have a citation as unstructured text — copied from a PDF, a scanned bibliography, or a manuscript’s reference list — and you need the DOI, but you don’t have clean structured fields (exact title, ISSN, volume/issue) to search on individually.

How it works

The tool is a plain web form at doi.crossref.org/simpleTextQuery. A user pastes one reference, or a full reference list (up to 1,000 entries per submission), and Crossref runs its citation-matching algorithm against the corpus of metadata its member publishers have deposited. For each reference it attempts to return a single best-match DOI. Because matching against loosely formatted text is inherently probabilistic, an optional setting lets the user list all plausible DOI candidates for a reference instead of just the top match, which matters when a citation is ambiguous (a common short title, a reprinted edition, multiple editions of the same work). Crossref also notes that unmatched references are retained and periodically re-checked, since a DOI may not exist for an item yet at the time of the original query.

Who uses it, and why

Typical users include librarians and copy editors reconciling a reference list that predates consistent DOI assignment, researchers recovering a DOI for a citation they only have as text, and anyone reference-linking a document without access to a bibliographic-reference manager already populated with DOIs. Because it requires no Crossref membership, login, or fee, it is also commonly used by people outside Crossref’s member publishers — it is a public utility layered on top of the Crossref metadata index, not a member-only production tool.

Relationship to the Crossref REST API

Simple Text Query’s web form is a convenience interface over the same free-text matching capability exposed programmatically through the Crossref REST API’s query.bibliographic parameter on the /works endpoint. A call such as api.crossref.org/works?query.bibliographic=<citation string> performs the equivalent match and returns structured JSON results (candidate works with their DOIs, titles, authors, and scores) rather than a web-page result list. This is the form used by automated pipelines — for example, a publisher’s production workflow matching an entire reference list to DOIs as one batch step before depositing Crossref metadata for a new article, or a reference manager plugin resolving pasted citations in bulk. query.bibliographic replaced the now-deprecated query.title parameter and searches across titles, authors, ISSNs, and publication years in combination, which is why it tolerates messier, less-structured input than a field-specific search would.

Scope and limits

Simple Text Query only searches metadata that has already been registered with Crossref by a member publisher — it cannot find a DOI for content that was never deposited, and it returns nothing for references to works registered with other DOI registration agencies such as DataCite (used mainly for research data, software, and preprints from many repositories) unless that content happens to also be indexed by Crossref. It is a matching and lookup tool, not a metadata registration tool: it never creates or edits a Crossref DOI record, and using it has no effect on any publisher’s deposited metadata.

References

Crossref, ‘Simple Text Query’ (crossref.org/documentation/retrieve-metadata/simple-text-query/).
Crossref, REST API documentation, query.bibliographic parameter (github.com/CrossRef/rest-api-doc).

Use in your systems

JATS XML <role> element

xml

<role vocab="credit"
      vocab-identifier="https://casrai.org/dictionary/"
      vocab-term="Crossref Simple Text Query"
      vocab-term-identifier="https://casrai.org/dictionary/term/crossref-simple-text-query" />

Schema.org DefinedTerm (JSON-LD)

json

{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "@id": "https://casrai.org/dictionary/term/crossref-simple-text-query",
  "name": "Crossref Simple Text Query",
  "identifier": "https://casrai.org/dictionary/term/crossref-simple-text-query",
  "description": "<p>Crossref Simple Text Query is a free web-based matching tool at <a href='https://doi.crossref.org/simpleTextQuery' target='_blank' rel='noopener'>doi.crossref.org/simpleTextQuery</a> that takes an unstructured reference or reference list &#8212; pasted as plain citation text, not structured fields &#8212; and returns the matching DOI for each item it can identify. A submission can hold up to 1,000 references, entered one per line or block, and the tool attempts to return exactly one best-match DOI per reference by default (an option to list all possible matches is available when a reference is ambiguous). No Crossref membership or account is required to use it, and there is no charge. The same underlying free-text matching is also exposed programmatically through the Crossref REST API's <code>query.bibliographic</code> parameter on the <code>/works</code> route (for example <code>api.crossref.org/works?query.bibliographic=your+citation+string</code>), which is the machine-actionable equivalent of pasting a citation into the web form &#8212; useful for batch reference-linking pipelines rather than one-off lookups.</p>",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/persistent-identifiers#set",
  "url": "https://casrai.org/dictionary/term/crossref-simple-text-query",
  "sameAs": [],
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "publisher": {
    "@id": "https://casrai.org/#organization"
  },
  "dateModified": "2026-07-18T06:30:56",
  "inLanguage": "en"
}