Paste a list of citations in any style: MLA, APA, Chicago, a DOI, a link, or a line you half remember. Historia looks each one up in real catalogues and shows the record it found, with its link and anything that differs from the entry. No AI reads your list: each line is read and matched by code.
Each line is read by code for its DOI, link, ISBN, title, authors and year. Historia then asks Crossref, OpenAlex, Open Library and the Library of Congress, and opens the link if there is one. “Found” needs a title that matches closely and an author that agrees (or, for an entry with no author, the year). A real title with a new subtitle, a real author with a different title, or a real journal with the wrong year is at most a close match, with the difference shown.
“Not found” does not mean fake. It means the catalogues Historia checked hold nothing close enough. Many real sources are not in them: archival letters, local newspapers, theses, government reports, small-press and very recent books. Check a library catalogue or ask a librarian. This page is for checking your own work, and for teachers helping students check theirs. It is not evidence that anyone did anything wrong.
Your list is sent to Historia’s server for this one check. It is not saved, cached or logged. The words of each entry are sent to the catalogues named above, and a cited link is opened by Historia’s server. As with searches, a random browser id and a hash of your network address are kept for a short time to limit how many checks can be run.