Thomson Reuters AI assistant for legal professionals, now integrated into Westlaw Precision and CoCounsel Core, providing AI-powered legal research, document analysis, and contract review capabilities.
Thomson Reuters AI assistant for legal professionals, now integrated into Westlaw Precision and CoCounsel Core, providing AI-powered legal research, document analysis, and contract review capabilities.
CoCounsel is Thomson Reuters' AI-powered legal assistant that delivers AI-driven legal research, contract analysis, and document review grounded in the Westlaw database of over 40,000 curated legal sources. For attorneys seeking to reduce research time while maintaining citation accuracy, CoCounsel offers a compelling solution — particularly for firms already embedded in the Thomson Reuters ecosystem.
Originally launched by Casetext in 2023, CoCounsel was acquired by Thomson Reuters in August 2023 for approximately $650 million, signaling the company's aggressive investment in AI-powered legal technology. Since the acquisition, Thomson Reuters has progressively integrated CoCounsel's AI capabilities into its flagship Westlaw Precision platform, creating a seamless experience where attorneys can conduct AI-assisted research within the same interface they already use for traditional legal research.
CoCounsel's core strength lies in retrieval-augmented generation grounded in Westlaw's editorially curated legal databases. Unlike general-purpose AI tools such as ChatGPT that rely on broad internet training data, CoCounsel draws from verified case law, statutes, regulations, and secondary authority curated by Thomson Reuters' team of attorney editors. Every AI-generated response includes direct citations to specific Westlaw sources, enabling attorneys to verify outputs and maintain professional responsibility obligations.
Key capabilities include natural language legal research across jurisdictions, AI-generated research memoranda, contract analysis for due diligence and compliance workflows, document summarization and extraction, and deposition preparation assistance. The contract analysis module is particularly notable for its ability to process large document sets — such as hundreds of leases or vendor agreements during M&A due diligence — and identify non-standard clauses, missing provisions, and deviations from market norms.
As of 2025-2026, CoCounsel exists across multiple product tiers. Westlaw AI-Assisted Research embeds CoCounsel capabilities directly within the Westlaw Precision interface for existing subscribers. CoCounsel Core provides a more accessible entry point with foundational AI research and document review features for smaller practices. The full CoCounsel platform includes advanced contract analysis, batch document processing, and expanded workflow integrations.
The platform has been adopted by over 1,000 law firms and corporate legal departments, reflecting significant enterprise validation. Thomson Reuters reports that tasks such as multi-jurisdictional research that might take a junior associate 8-10 hours of manual Westlaw searching can be reduced to under an hour with CoCounsel, though attorneys must still review and verify all AI-generated outputs.
CoCounsel operates on Thomson Reuters' secure cloud infrastructure with SOC 2 Type II compliance. Client data uploaded for document review is not used to train AI models, and the system maintains data isolation between firm accounts with full audit trails documenting which sources informed each output.
The primary limitation is pricing transparency: Thomson Reuters does not publish public pricing, and enterprise contracts are negotiated through sales. Industry estimates place per-user costs at several hundred dollars per month when bundled with Westlaw Precision, making it one of the more expensive legal AI options but potentially cost-effective for firms already paying for Westlaw access. Firms using competing research platforms like LexisNexis may face significant switching costs.
Was this helpful?
CoCounsel's research capability is grounded in Westlaw's 40,000+ legal databases, enabling attorneys to pose natural language questions and receive structured memoranda with pinpoint citations to case law, statutes, and secondary authority. Unlike general-purpose AI tools, CoCounsel's retrieval-augmented generation approach pulls directly from editorially curated legal content, including attorney-written headnotes and the West Key Number System. The integration into Westlaw Precision means attorneys can initiate AI-assisted research without leaving their existing workflow, and can seamlessly navigate from AI-generated citations to full-text authority within Westlaw.
The contract review module can ingest and analyze large document sets — such as hundreds of leases or vendor agreements — to identify non-standard clauses, missing provisions, and deviations from market norms. Results are organized into structured reports that categorize findings by risk level and clause type, enabling attorneys to prioritize review efforts. This capability is particularly valuable during M&A due diligence, where transactional teams need to review 200+ contracts efficiently while ensuring no material terms are overlooked.
Every AI-generated response includes direct citations to specific Westlaw sources, with links to the full-text authority. The platform maintains complete audit trails documenting which sources informed each output, directly supporting attorneys' professional responsibility obligations under rules requiring competent supervision of AI tools. This source attribution model distinguishes CoCounsel from general-purpose AI tools that cannot reliably cite legal authority.
Attorneys can upload briefs, filings, contracts, or regulatory documents and receive structured summaries identifying key provisions, parties, obligations, deadlines, and potential issues. The system can process documents up to several hundred pages in length and extract specific data points into organized formats suitable for client reporting or internal analysis. This feature reduces the time attorneys spend manually reviewing lengthy documents while ensuring critical details are surfaced consistently.
CoCounsel analyzes deposition transcripts alongside case materials to suggest lines of questioning, identify inconsistencies in witness testimony, and flag areas requiring further investigation. This capability integrates with the broader research functionality, allowing attorneys to cross-reference deposition testimony against relevant case law and statutory authority. Litigation teams can use these features to prepare more thoroughly for depositions and identify potential impeachment opportunities.
Custom enterprise quote
Add-on to Westlaw Precision subscription
Custom enterprise quote
Ready to get started with CoCounsel?
View Pricing Options →A litigation team handling a product liability case across 8 states can use CoCounsel to simultaneously research relevant statutes of limitation, product liability standards, and recent case law in each jurisdiction. The AI synthesizes findings into a comprehensive memorandum comparing each state's legal framework, with pinpoint citations to controlling authority. This replaces days of manual research with a structured starting point that attorneys can refine and verify, dramatically accelerating case preparation timelines.
A transactional team reviewing 200+ vendor contracts during acquisition due diligence can upload the document set to CoCounsel for batch analysis. The system identifies change-of-control provisions, assignment restrictions, termination clauses, and non-standard indemnification terms across all contracts, organizing findings into structured reports by risk category. This enables attorneys to focus review time on the highest-risk agreements rather than reading every contract cover to cover.
A solo employment law attorney preparing for a wrongful termination hearing can use CoCounsel to quickly research relevant precedent, identify key cases supporting their theory of the case, and generate a draft research memo. This levels the playing field by giving small firms access to research capabilities that previously required teams of junior associates, enabling solo practitioners to handle complex matters more efficiently without sacrificing research thoroughness.
A corporate legal department tracking regulatory changes across multiple jurisdictions can use CoCounsel to analyze new regulations and compare them against existing company policies and contracts. The tool helps identify gaps between current practices and new requirements, enabling proactive compliance updates before enforcement deadlines. This is particularly valuable for companies in highly regulated industries operating across multiple states or countries.
An attorney preparing for a key witness deposition in a commercial dispute can feed prior deposition transcripts, interrogatory responses, and document production into CoCounsel. The system identifies inconsistencies across testimony, flags potential areas of vulnerability, and suggests lines of questioning based on the case record. This preparation capability helps attorneys enter depositions better prepared to pursue productive lines of inquiry and identify impeachment opportunities.
A firm's appellate practice group can use CoCounsel integrated with Westlaw Precision to research and draft sections of appellate briefs, pulling relevant authority and synthesizing arguments. The AI-generated drafts serve as starting points that attorneys refine with their own analysis and advocacy skills, reducing the initial drafting time while ensuring comprehensive coverage of relevant precedent and statutory authority.
We believe in transparent reviews. Here's what CoCounsel doesn't handle well:
Weekly insights on the latest AI tools, features, and trends delivered to your inbox.
Through 2025 and into 2026, Thomson Reuters has continued to roll out agentic capabilities in CoCounsel, allowing the assistant to chain multiple skills together to complete multi-step workflows such as end-to-end deposition prep or full contract review cycles with minimal lawyer intervention. AI-Assisted Research in Westlaw Precision has expanded to additional practice areas and jurisdictions, and integrations with Practical Law and Checkpoint have deepened so that tax and transactional workflows benefit from the same conversational interface. Thomson Reuters has also emphasized model flexibility, with CoCounsel running on a mix of frontier models from providers including OpenAI and Anthropic depending on the task, and has continued investing in evaluation and benchmarking to address concerns about hallucinations and output reliability in professional settings.
No reviews yet. Be the first to share your experience!
Get started with CoCounsel and see if it's the right fit for your needs.
Get Started →Take our 60-second quiz to get personalized tool recommendations
Find Your Perfect AI Stack →Explore 20 ready-to-deploy AI agent templates for sales, support, dev, research, and operations.
Browse Agent Templates →