Citation Checker

Paste your reference list. We check every entry, walk you through anything that is wrong, and give you back a clean list in the style you need.

The Citation Checker matches each reference against Crossref, PubMed, OpenAlex, Europe PMC, Semantic Scholar, DataCite, Open Library and the DOI registries, and flags fabricated citations, retracted papers, broken DOIs, wrong years and author or journal mismatches. A reference is marked verified only when a real registry record matches it. You can then filter what needs review, replace a reference with the registry version, and reformat the whole list into any of 10,800+ citation styles.

Free, runs in your browser. Nothing you enter is uploaded.

What you get

Questions

How do I check my citations?

Paste your reference list, one entry per line or numbered, or upload a .docx, .bib, .ris or .txt file, and click Check references. Each entry is looked up in up to eight registries and marked verified, check needed, wrong DOI, uncertain or not found. Use the Needs review filter to work through only the flagged ones.

Can it find fake or AI-generated citations?

Yes. A made-up reference does not exist in any registry, so it comes back as not found. A real paper cited with an invented DOI is flagged as wrong DOI.

Which citation styles does it read?

Any. APA, MLA, Vancouver, AMA, Harvard, Chicago and plain lists all work. It pulls out the title, authors, year and any DOI or PMID regardless of format.

Is a verified reference always correct?

Verified means a real record matches the title, authors and year. It does not judge whether the source supports your claim. Textbooks, theses, preprints and small regional journals can show as uncertain even when real, so check those by hand.

Is my reference list stored?

No. Lookups run in your browser straight against the public registries, and your last check is kept only in this browser so a refresh does not lose it. If you use AI review, the flagged references are sent to an AI model to explain them; nothing is stored on this site.

Can it reformat my references into another style?

Yes. Click Reformat list and pick APA, MLA, Chicago, Vancouver, Harvard, IEEE, AMA, a specific journal from 10,800+ styles, BibTeX or RIS. Formatting uses the registry record, so names, volumes and pages come out correct.

What does the AI review do?

For references that could not be confirmed, AI explains the likely problem in plain English and works out what you probably meant. The checker then searches the registries again and offers real matching papers. AI never marks a reference as verified; only a registry record can.

Does it flag retracted papers?

Yes. Retractions recorded in Crossref, PubMed, Europe PMC or OpenAlex show as a major issue on that reference, and the Retracted filter lists them together.

Related reading

More Research & Writing

All free tools · By Dr. Zubair Khalid, DVM, MS, PhD.