CaseStrainer

CaseStrainer is an experimental, free, and open-source utility designed to validate U.S. case citations in legal documents.

Unlike generative AI tools that may introduce hallucinated or fabricated cases, CaseStrainer strictly focuses on citation verification. Users can paste text, upload documents (PDF, DOCX, TXT, RTF, MD, HTML, XML), or provide URLs, and the system automatically extracts and checks all case citations against authoritative legal databases.

The tool outputs a confirmation of validity for each citation, flagging any unrecognized or suspect references. It could be useful for lawyers, researchers, and students who rely on accurate case law references, and who need a quick way to catch errors before filing, publishing, or relying on a document.

It relies on CourtListener and other free sources to validate cases. Right now, no paid APIs are required, though they could be added in the future.

The Github repository for CaseStrainer here: https://github.com/jafrank88/casestrainer

CaseStrainer is not powered by generative AI, ensuring results are deterministic, transparent, and reproducible. While experimental and not a substitute for professional judgment, it provides a valuable safeguard against the growing risk of fabricated case law in an AI-augmented legal environment.

How to Assess Services Providing This Task:
When evaluating citation-verification tools like CaseStrainer, consider:

• Database Coverage – Does the tool check citations against authoritative and up-to-date sources (e.g., court databases, major legal research systems)?
• Accuracy & Precision – How reliably does it distinguish between valid citations and incorrect or hallucinated ones?
• Workflow Integration – Are there plugins or APIs (e.g., browser extensions, Word add-ins) that make it usable in real legal drafting workflows?
• Transparency – Does the system clearly show its verification process and sources?
• Risk Management – Is it framed as a supplement to, not a replacement for, professional research?