Casetext no longer exists as a separate product. Thomson Reuters bought the company in 2023 and retired the standalone Casetext platform on April 1, 2025. If you searched for Casetext, casetext.com now redirects straight to CoCounsel, the AI legal assistant Thomson Reuters built from Casetext’s technology. This review explains what happened to Casetext, what CoCounsel does today, and whether it suits your firm. CoCounsel handles legal research, contract review, deposition preparation, and drafting inside the Westlaw and Practical Law ecosystem. It works best for firms that already pay for Thomson Reuters content and want an AI layer on top of it.
What Is Casetext (Now CoCounsel)?
Casetext was founded in 2013 by Jake Heller in San Francisco as a legal research platform, known for its CARA AI contextual search. In March 2023, Casetext launched CoCounsel, one of the first legal AI assistants built on GPT-4. Thomson Reuters acquired Casetext for 650 million dollars in cash in August 2023 to fold that technology into its own AI strategy. Thomson Reuters retired the standalone Casetext product on April 1, 2025, then relaunched a rebuilt CoCounsel Legal in August 2025 with Deep Research and agentic, multi-step workflows.
How Does CoCounsel Work?
A lawyer describes a task in plain language, and CoCounsel works through it the way a colleague would, rather than returning a single short answer. Thomson Reuters has described a governed, multi-model architecture behind CoCounsel that draws on Claude, Chat GPT, Gemini, and proprietary models depending on the task. Deep Research grounds its output in Westlaw content and shows sources a lawyer can check. Matter workspaces organize work by case, and Tabular Analysis can review up to 10,000 documents against up to 100 questions in one table.
Key Features
- Deep Research grounded in Westlaw case law and secondary sources
- Contract drafting, clause modification, and playbook checks
- Deposition preparation support
- Document review at scale through Tabular Analysis
- Knowledge Search across firm and licensed content
- Native integration with Microsoft Word, Teams, and Outlook
Performance and Experience
Thomson Reuters has stated that the original CoCounsel went through close to 4,000 hours of testing against more than 30,000 legal questions before launch. By February 2026, the company reported roughly one million CoCounsel users across 107 countries and territories. Thomson Reuters also reports use by more than 20,000 legal teams, including 80 percent of the Am Law 100. The interface itself is straightforward, though the wider learning curve comes from understanding which Thomson Reuters product, such as Westlaw Advantage or Practical Law, unlocks which CoCounsel capability. See how it compares with other business and enterprise AI tools we cover.
Data & Market Position
CoCounsel has become one of the leading AI legal assistants after Thomson Reuters integrated Casetext’s technology into its broader legal ecosystem. The platform is designed around enterprise-level legal workflows, combining AI reasoning with trusted legal databases, document intelligence, and professional research tools. Unlike general-purpose AI assistants, CoCounsel focuses on reducing time spent on complex legal tasks such as case analysis, contract review, regulatory research, and litigation preparation. Its strongest advantage is access to Thomson Reuters’ legal content and citation-backed outputs, making it particularly valuable for firms that require accuracy, compliance, and auditability. However, smaller firms and independent lawyers may find the enterprise pricing model and dependence on Thomson Reuters subscriptions less accessible compared with standalone legal AI alternatives.
Integrations and Compatibility
CoCounsel runs as a web app and integrates directly with Microsoft Word, Microsoft Teams, and Microsoft Outlook. Its deepest ties are internal, to Westlaw and Practical Law, rather than to third-party legal software outside the Thomson Reuters ecosystem. Sources also note a Claude Desktop connection through MCP. No public developer API for outside integrations was confirmed in current Thomson Reuters materials.
Imperial AI Tools Feedback
CoCounsel’s strength is trust: it grounds answers in licensed Westlaw and Practical Law content and shows its sources, which matters for legal work a lawyer must stand behind. Adoption numbers, including reported use across 20,000 legal teams, support that this is a mature, widely deployed product rather than an early-stage experiment. The weakness is access. Thomson Reuters has not published a clear self-serve price, and the tool works best bundled with a Westlaw or Practical Law subscription. Former Casetext users who wanted an affordable standalone research tool no longer have that option inside the Thomson Reuters family, and competitors such as Harvey are competing hard for the same enterprise buyers.
Suggestions For Improvement
- Publish transparent self-serve pricing instead of requiring a sales call for every tier.
- Offer a lower-cost plan for solo lawyers and small firms, closer to what Casetext once provided.
- Reduce the dependency on a separate Westlaw or Practical Law subscription for core features.
- Give former Casetext users clearer migration and pricing guidance on the redirect page.
- Expand integrations beyond the Microsoft 365 ecosystem.
