Learn About: Bluebook 21st Indigo Book ALWD 7th LII Basic Citation UCG 3rd

Cite Commons Citation Checker

An AI companion for checking citations and reinforcing citation skills — because legal citation belongs to all of us, not one book.

Why Case Law Matters ↗
β Beta Cite Commons is in public beta. Results are AI-assisted and may contain errors — always verify against primary sources. (We will always say this, even when the technology has been perfected.) Always be the human in the loop! Found a bug or have a suggestion?
? How to Use Cite Commons
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  • Paste your citations into the text box — one citation per line, or multiple in a paragraph. Cite Commons will detect and analyze each one individually.
  • Choose which guide(s) to check against using the Check buttons: select a single guide (Bluebook, Indigo, ALWD, UCG, or LII) or run all five at once with All 5.
  • Select a modeDetailed provides rule citations, explanations, and corrected forms; Quick gives a fast pass/fail with the primary rule reference only.
  • Click Check Citations to submit. The AI will analyze each citation and return a status (✓ Correct, ⚠ Review, or ✕ Error Found) for each applicable guide.
  • Review results by expanding each citation card. Switch between guide tabs to compare how the same citation is treated across different standards. A comparison table appears at the bottom when checking all guides.
  • Corrected forms are shown in a highlighted box when errors are detected — copy these directly into your document.
  • Sample citations are available below the guide selector to help you explore the tool's capabilities.

How This App Works & Its Limitations Cite Commons sends your citations to an AI language model (Claude by Anthropic) along with embedded rule text for each guide. The Indigo Book (CC0), LII Basic Legal Citation, and UCG (3rd ed.) are directly grounded — meaning rule text was extracted from the source documents and is included in the AI's instructions. Bluebook (21st ed.) and ALWD Guide (7th ed.) are checked using the AI's training knowledge, which is comprehensive but is not a direct reference to the published texts.

Cite Commons is an AI-assisted learning and drafting aid — not a substitute for consulting the authoritative guide directly. Citation rules change across editions, jurisdictions, and document types. Always verify important citations against the primary source. Results may contain errors; treat them as a starting point for review, not a final answer.
Filing your own court documents?

If you're representing yourself in court (pro se), proper citations help judges and clerks find the authorities you're relying on. Use the Bluebook or ALWD guides for federal courts. State courts often have their own rules — check your court's local rules first. Cite Commons can check citations for any of these guides. When in doubt, the most important thing is that your citation gives the reader enough information to find the source: case name, volume, reporter, page number, and year for cases; title, code abbreviation, section, and year for statutes.

Citation Guide Sources Loading…
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Bluebook 21st Ed.
The standard law review guide (2020). Rules R1–R21 + Bluepages B1–B21. Comprehensive training knowledge.
Training knowledge
Indigo Book 2d Ed.
CC0 public domain (2016/2021). Rules R1–R40 + Tables T1–T20. Embedded directly from law.resource.org.
Loading rules…
ALWD 7th Ed.
Association of Legal Writing Directors (2021). Practitioner-focused, including key differences from Bluebook.
Training knowledge
LII Basic Citation
Cornell LII "Introduction to Basic Legal Citation" (Peter W. Martin, 2020). Practitioner-focused; documents divergence from Bluebook. Grounded from LII PDF: cases, statutes, regs, court rules, books & articles.
Web-grounded (law.cornell.edu)
UCG 3rd Ed.
AALL Universal Citation Guide (2014). Medium-neutral/vendor-neutral rules 100–707 for judicial decisions, statutes, regs, court rules & law reviews.
Training knowledge
Grounded (rule text embedded): Indigo Book (CC0), LII Basic, UCG Synthesized from training: Bluebook 21st ed., ALWD 7th ed. — comprehensive but not a direct rule-text reference
Check:
Depth:
CourtListener Live Lookup — add token to enable real-time case verification
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Cite Commons can verify whether federal case citations actually exist by querying the CourtListener database (Free Law Project). This requires a free API token. Here's how to get one:

  1. Go to courtlistener.com/sign-in and create a free account (or log in).
  2. Click your username in the top-right corner, then select Profile.
  3. Scroll down to the API Token section — your token is shown there.
  4. Copy the token and paste it into the field below, then click Save.

The token is stored only in your browser's session memory and never sent anywhere except CourtListener.

API Token:

Without a token: AI existence assessment + Caselaw Access Project lookup for state cases (free, no token needed).
With a token: AI assessment + live CourtListener lookup (federal & recent state) + CAP (deep historical state).

About Caselaw Access Project (CAP): The Caselaw Access Project (Harvard Law School) has digitized over 40 million U.S. state court decisions from 1658 to approximately 2018–2021. Coverage completeness varies by state and ends when Harvard finished scanning that state's print reporters — cases decided after that cutoff will not appear in CAP even if they exist. For recent state cases (roughly 2020 and later), a "not found" result from CAP does not indicate the case is fictitious; verify against the court's official website or a commercial service.


Optional: Use your own Anthropic API key. By default Cite Commons uses a shared key provided by the site. If you have your own Anthropic API key, you can use it instead — your checks will run on your own quota and the shared key won't be used. Your key is stored only in this browser session and never logged.

Anthropic Key:

Get a free key at console.anthropic.com. Usage is billed to your account at Anthropic's standard rates.

Build a Citation — describe what you're citing
Generates properly formatted citations from the information you provide
Generated Citations
Upload a document to extract and verify its citations
Drop a file here or click to browse
PDF · Word (.docx) · Plain text (.txt)
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Privacy notice Your file is read entirely in your browser and is never uploaded or stored anywhere. The text extracted from it is sent to Anthropic's API to identify citations — the same as typing or pasting text into the checker. Do not upload documents containing confidential, privileged, or sensitive information (draft briefs, client memos, sealed materials). Anthropic's API privacy policy applies to text sent via this tool. Nothing is retained after you close or refresh the page.
Practice tip: You can also extract citations from a document yourself — copy them into a plain text file, one per line — and paste or import that list directly into the Citation Checker tab. This gives you full control over which citations to check and keeps your document contents off the network entirely.
Extracts all citations from your document, then checks them against the selected guides
Reading document…
Try an example:
SCOTUS case Universal/public domain cite Federal statute Book Law review Fed. rule Constitution Admin. reg.
See a sample result before you start ▾ show example
This is what Cite Commons returns for: Brown v. Board of Education, 347 U.S. 483 (1954).
Brown v. Board of Education, 347 U.S. 483 (1954).
Errors Found case
Existence: ✓ Confirmed (AI)
Landmark U.S. Supreme Court case (1954) holding racial segregation in public schools unconstitutional. Correctly reported at 347 U.S. 483.
BB ✕
IB ✕
AL ✕
LII ✕
UCG ✓
✕ Error Found
Under Bluebook T6, "Board" must be abbreviated to "Bd." and "Education" to "Educ." when the case name appears in a citation clause. The reporter, volume, page, and year are correct. No court identifier is needed for U.S. Reports per Rule 10.4(a).
Corrected Form
Brown v. Bd. of Educ., 347 U.S. 483 (1954).
§ Rule 10.2.1(c), T6, T1.1
Recent checks 0 ▾ details
Enter citations — one per line or paste a passage 0 chars
Loading Indigo Book rules…
Consulting the guides…
Applying grounded rule text
Analysis Results
Summary