Loupe Citation Checker

Loupe checks the authorities cited in United States legal writing (cases, statutes, regulations, court rules and links) against the sources that settle them, and says plainly which checks ran and which did not.

With Loupe connected, Claude can:

• check a passage or a whole draft, finding cases that do not exist, citations that lead to a different case, pin cites outside the opinion, wrong years or reporters, and dead links;
• check a single citation;
• find a case by name in Loupe's index of American case law;
• verify that quoted words are in the opinion they are attributed to, and whose words they are (Solo and Firm plans);
• make a sealed record of a check, kept in the user's Loupe account and verifiable at loupe.legal/verify (Solo and Firm plans).

How it checks: no language model is asked whether a citation is right, and nothing is generated. Whether a case exists is answered from Loupe's own index, built from public-domain court data with the page ranges of close to seven million opinions. Statutes and regulations are asked of their publishers: the House's U.S. Code, GovInfo, the eCFR, Congress.gov and the Federal Register. A citation Loupe could not settle is reported as not verified, never as correct and never as wrong.

What it does not do: it does not say whether a case is still good law or whether it supports the point. That remains the lawyer's reading. It is not legal advice.

Users sign in with a Loupe account, which is free. The text sent for checking is not kept.