Compared · read 2026-09-24
Every free case-citation checker we read confirms that a citation points to a real case, and most of them do it by asking CourtListener. Fewer check the quotation or whether the case supports the point, one shows citator flags, and none of the others publishes how often its own checks are wrong. Each row below comes from the tool's own pages, read on 2026-09-24.
| tool | free tier | case exists | name matches | quotation | supports the point | still good law | own error rate published | checks against | your text |
|---|---|---|---|---|---|---|---|---|---|
| proofread.law | 20 checks and 3 deep checks a month, no account | yes | yes | yes | yes, opt-in deep check | no | yes, measurements | its own register, built from CourtListener bulk data, govinfo and the Caselaw Access Project | not stored unless you save it |
| CourtListener citation lookup | free; the API needs a free token | yes | not stated | not stated | not stated | not stated | no | CourtListener's own database | not stated |
| LegalCite (legalcite.io) | 20 checks a day, no signup | yes | yes | no | no | no | no | CourtListener | processed in memory and discarded; sent on to CourtListener's lookup |
| Is This Case Real | free, up to 20 citations or 5,000 words at a time | yes | not stated | not stated | not stated | not stated | no | Free Law Project data and tools | not stated |
| CiteCheck AI (citecheck.ai) | 15 reports free, with an account | yes | not stated | yes | not stated | not stated | no | CourtListener API | not stated |
| CaseRead Hallucination Shield | 2 checks a day, up to 50 citations each; an email address unlocks the full result | yes | not stated | not stated | yes | not stated | no | CourtListener for cases, OpenLaws for statutes; the support check uses Anthropic's Claude and a Brave web search | not kept; sent to Anthropic for the support check |
| CiteDiver (LawDiver) | free during rollout, account required, US users only | yes | not stated | says it flags misquoted authority; no method described | not stated | yes, flags (overruled, questioned, reversed and others) | no; it states a 99.9% accuracy target for overruled status, not a result | its own corpus, started from the Caselaw Access Project and CourtListener | documents you submit are collected; account data kept while the account is active |
| OpenCaseLaw (Swiss law) | open data and an MCP server with no sign-in; its pages differ on whether the Word add-in's Audit is free or part of a CHF 5 a month plan | yes, with pinpoints | not stated | yes, quotations of 30 characters or more | yes, opt-in | not stated | no (its published percentages measure coverage and search, not the checks) | Swiss official court sources | never stored on its server |
"Not stated": the tool's own pages do not say. "Yes" for the other tools is the tool's own claim; for ours it is measured. Google Scholar is left out of the table because it is a search engine, not a checker (see below). A tool called Cite Commons came up in our research; its site showed only "Launching Soon", so it is not listed.
A free, non-profit case-law site. The lookup page takes one citation you know and takes you to the case: "If you have a citation you want to look up, put it in here, and we'll look it up." Its own caveat: "This tool is limited by the citations that we have in our system." The citation lookup API reads a block of text and looks up every citation in it: "Text lookup requests to this API can only contain 64,000 characters at a time" and "This API will only lookup 250 citations in a single request." It "does not look up statutes, law journals, id, or supra citations." For a single citation you want to read in full, it is the tool to use.
courtlistener.com/c/ · courtlistener.com/help/api/rest/citation-lookup/ · read 2026-09-24
A search engine with a case law collection: "published opinions of US state appellate and supreme court cases since 1950" and "US federal district, appellate, tax and bankruptcy courts since 1923 and US Supreme Court cases since 1791". Search the citation in quotation marks and check the case it lands on. Its help page says: "Google does not warrant that the information is complete or accurate."
scholar.google.com/intl/en/scholar/help.html · read 2026-09-24
Checks whether each citation is "real (the case exists and the name matches…)" or a "name-mismatch", and "resolves each against CourtListener (public court records)". It states its limits plainly: "It does not assess legal correctness, holdings, or good-law status." Free tier: "Free tier is 20 checks/day." and "No signup"; paid: $29 a month. It has an MCP server. On storage: "Submitted text is processed in memory and discarded when the request completes", and "the text you submit is forwarded to CourtListener's citation-lookup API".
legalcite.io · legalcite.io/pricing.html · legalcite.io/privacy.html · read 2026-09-24
"Check for Hallucinated Cases for Free", "up to 20 cites or maximum of 5,000 words at a time". It uses "data and tools from the amazing team at Free Law Project" and asks users to "double-check our double-checking". Its terms say it "does not collect any personally identifiable information from user"; they do not say whether pasted text is kept.
isthiscasereal.com · isthiscasereal.com/terms.html · read 2026-09-24
From LawDroid. Its page shows no text without JavaScript; the lines here are from the app's interface. It checks existence ("verify that all case citations are real, existing cases") and quotations ("The quoted text was not found in the source opinion."), "Verified via CourtListener API". Free: "15 Reports Free!" with a free account; paid plans start at $25 a month for 100 reports. The "Accuracy Rate" it shows is the share of your own citations that came back valid, not a rate for its checks.
citecheck.ai · read 2026-09-24
"Two checks on every citation: does the source exist, and does it support the claim." Cases go to CourtListener and statutes to OpenLaws, so it covers statutes, which ours does not. The free tier: "every visitor gets 2 checks per day", up to 50 citations a run. It "does not persist the pasted text", and the text goes to Anthropic for the support check. Its page says: "Accuracy depends on the coverage of the sources we look up." Paid: $149 a seat a month, or $119 billed yearly.
caseread.ai/hallucination-shield · caseread.ai/pricing · read 2026-09-24
Checks whether a citation resolves "to a real opinion in the LawDiver corpus" and shows "Overruled, questioned, distinguished, subsequent history, and reversal flags", which makes it the only free tool here with citator flags. It is "Free during rollout", with an account, for US users; afterwards "cite checks are metered at 3¢ per citation". Its blog gives a target, not a measured result: "Our target operating claim is 99.9% accuracy on detecting overruled status". It advises: "Always read the authority for the proposition you cite."
lawdiver.com/products/citediver · lawdiver.com/privacy · lawdiver.com/blog/how-lawdiver-caselaw-database-assembled · read 2026-09-24
Open data ("Open data (CC0)") and an MCP server with "no authentication". Its tools check that "every BGE/BGer/BVGer/BStGer/BPatGer/MKGE reference exists, every pinpoint resolves", that quotations "of ≥30 chars" appear "verbatim in a cited source", and, as an option, "whether the cited source actually supports the proposition". Its README calls the Word add-in's Audit free; the add-in's terms list it under "Pro tier. CHF 5 per month." On storage: "Document text is never stored on our server". For Swiss law it is the other open option. Ours checks Swiss citations too; the coverage page lists what our Swiss register holds.
opencaselaw.ch · opencaselaw.ch/mcp/ · github.com/jonashertner/opencaselaw · word.opencaselaw.ch/terms.html · word.opencaselaw.ch/privacy.html · read 2026-09-24
What ours adds: the quotation check in the free tier, a support check (opt-in) that shows the passage, and a published error rate for every check, with its sample and caveats. What it lacks: citator flags (CiteDiver shows some; KeyCite and Shepard's are the full version), statutes (CaseRead checks them), and Westlaw or Lexis ids, which no open tool resolves. If you need one citation looked up, CourtListener is enough. If you need a whole draft checked with the evidence on each row, see what our report looks like or read how to check a citation by hand first. The paid tools, Westlaw, Lexis, CoCounsel, Clearbrief and BriefCatch, are on the main comparison.
If a tool's page changes, tell us at hello@proofread.law and the row changes.