CoCounsel
Thomson Reuters' AI legal assistant built on GPT-4 for legal research, contract review, and deposition analysis.
What it does
CoCounsel is Thomson Reuters' AI legal assistant - originally developed by Casetext and now integrated into the Thomson Reuters ecosystem alongside Westlaw. It performs substantive legal tasks from natural language instructions: researching case law and statutes and synthesizing findings into analysis, reviewing contracts and identifying key provisions and risks, analyzing deposition transcripts for key facts and inconsistencies, drafting legal memos and correspondence, and summarizing lengthy legal documents. CoCounsel's access to Westlaw's authoritative legal database gives it a significant advantage over general-purpose AI for US legal research accuracy - AI reasoning applied to trusted legal content.
Why AI-NATIVE
CoCounsel is AI-native - AI-powered legal research synthesis, document analysis, and substantive legal drafting from natural language instructions applied to authoritative legal databases are the core product capabilities.
Best for
Solo practitioners use CoCounsel to access associate-level research and review capabilities - AI enabling one attorney to handle workloads that would otherwise require additional staff.
Small law firms use CoCounsel for research and document review at speed - AI synthesizing case law and drafting memos faster than manual associate research.
Small in-house legal teams use CoCounsel for contract review and legal research - AI reducing dependence on external counsel for routine analysis.
Mid-market legal departments and law firms use CoCounsel systematically - document review, research, and drafting across the team with AI consistency.
Large law firms and corporate legal departments use CoCounsel at enterprise scale - high-volume document review and research acceleration on complex matters.
Limitations
CoCounsel can hallucinate citations or mischaracterize holdings — professional responsibility requires attorney supervision of all AI-generated work product before use.
CoCounsel's Westlaw integration and training data are strongest for US law — attorneys in non-US jurisdictions find coverage and accuracy reduced.
CoCounsel delivers the most value bundled with Westlaw — organizations not using Westlaw for research get less differentiated value from the integration.
Alternatives by segment
| If you need… | Consider instead |
|---|---|
| AI legal platform for large firms | Harvey |
| Contract review and CLM AI | Luminance |
| Litigation document review | Relativity |
CoCounsel from $117/month per attorney. Team plans available. Enterprise pricing negotiated through Thomson Reuters. Annual contracts. Westlaw subscription typically separate.
