What is a hallucinated (fake) citation?
A hallucinated citation is a reference to a source that doesn't exist — or one whose details have been altered so it no longer points to the real work. The term comes from “AI hallucination,” because large language models are now the most common cause.
Not the same as a sloppy reference
Researchers have always made citation mistakes: a transposed page number, a misspelled name, a wrong year. Those describe a real paper imperfectly. A hallucinated citation is different in kind — there is no real paper behind it, or the identifiers have been swapped so they resolve to a different work entirely.
The common forms
- Fully invented — plausible title, plausible authors, a journal that fits the field, and not a single real paper behind any of it.
- Real title, invented authors— a genuine paper's title attached to a fabricated author list.
- Identifier hijacking — a real-looking DOI or arXiv ID that actually resolves to a different paper. This is the form most checks miss.
- Altered metadata — a real paper relabeled with the wrong year, venue, or page numbers.
Why they suddenly matter
Language models produce confident, perfectly formatted references on demand — and a share of them are invented. A 2026 audit of 111 million references estimated roughly 146,932 fabricated citations in 2025 alone, with most slipping past preprint moderation and into the published record. Because later work builds on earlier reference lists, a fake citation can propagate long after it's introduced.
How to spot one
The reliable test is corroboration: does the work show up, with matching details, in authoritative databases? If a DOI resolves to a different title, if no index lists the paper, or if the authors don't match the real article, treat the citation as suspect. Doing this by hand for a whole bibliography is slow — which is the problem Hallucite automates. See how verification works.