Paste a bibliography; your browser checks every reference against six scholarly registries. Catches fabricated DOIs, AI-hallucinated citations and retractions. Free for everyone.
AI writes confident citations. Some of them don’t exist.
Fabricated DOIs, hallucinated papers, "stitched" citations that weld a real author to a real journal and a paper that was never written — they all look fine on the page. RefExists checks. Paste a bibliography and the browser itself verifies every reference against Crossref, DataCite, doi.org, OpenAlex, PubMed and Open Library, flagging what is real, what is retracted and what was never there.
DSL4 Digital engineers the client-side verification engine, registry integration and local MCP server. Viva Grafix designed around the no-upload security model, making the difference between evidence, uncertainty and a failed lookup understandable at a glance.
A tool about trust has to be structurally unable to betray it.
One input, checked across 250M+ scholarly works — DOIs resolved, metadata compared, retractions surfaced.
Detects the tell-tale LLM "stitched citation" signature — plausible fragments of different real works fused into one fake reference.
Ships with a keyless local MCP server exposing verify_citations, so AI agents can check their own homework.
DSL4 Digital’s architecture makes privacy provable and absence explicit; our design response is to make those distinctions legible rather than merely claimed.
A strict Content-Security-Policy allowlists only the six registry origins. The browser is physically prevented from sending your text anywhere else — enforced, not promised.
A network failure is not the same as "this paper doesn’t exist". A reference is only marked missing after a definitive registry 404 chain — the engine distinguishes "couldn’t check" from "checked, and it’s not there".
A 25-case test suite runs against the real registry APIs, covering the fabrication patterns we actually see.
RefExists is a DSL4 Digital public tool, with Viva Grafix shaping an interface for evidence rather than false certainty: MIT-licensed, free, and incapable of spying on you.