How the DOI lookup works
- Paste your reference list — one reference per line, any style (APA, Vancouver, or messy).
- Each entry is matched in CrossRef — the official DOI registry — using title, author, and year similarity. Entries that already contain a DOI are skipped.
- DOIs are appended in APA 7 format (https://doi.org/…). Confident matches are marked ✅, uncertain ones ⚠️ with the matched work shown so you can verify, and works with no DOI in CrossRef are labelled clearly.
Frequently asked questions
What is a DOI and why do my references need one?
A DOI (Digital Object Identifier) is a permanent link to a published work. APA 7 requires it — formatted as https://doi.org/… — at the end of any reference that has one. Journals routinely return manuscripts asking for missing DOIs.
Do all references have DOIs?
No. Most journal articles from roughly 2000 onward have one; many books, older papers, reports, and web pages don't. APA 7 simply omits the DOI in that case, so a "no DOI found" result can be perfectly fine.
How accurate is the matching?
Matching uses the same title-similarity scoring as our citation & reference checker. Confident hits require most of the title plus corroborating details to line up; anything less is flagged for manual verification rather than silently inserted.
Is my reference list uploaded anywhere?
No — the tool runs entirely in your browser and talks directly to the public CrossRef API. Your references never reach our servers.