{"slug":"cocounsel","name":"CoCounsel","domain":"thomsonreuters.com","verdict":"As of 2026-07-15, ChatGPT, Claude, Gemini, Grok collectively rank CoCounsel first for ai legal assistant (one of 2 leaderboards it appears on). Source: https://modelsagree.com/product/cocounsel (modelsagree.com, CC BY 4.0).","best_rank":1,"categories":2,"brief":{"category":"best-ai-legal-assistant","title":"Best AI legal assistant","rank":1,"of":8,"top":null,"day":"2026-07-16","why":[{"t":"Grounded in authoritative Westlaw","m":["ChatGPT","Gemini","Claude","Grok"],"q":"Deeply integrated with Thomson Reuters' authoritative Westlaw database"},{"t":"Reliable citation-backed legal research","m":["ChatGPT","Gemini","Claude","Grok"],"q":"highly reliable, citation-backed legal research"},{"t":"Dependable document analysis","m":["ChatGPT","Gemini","Claude","Grok"],"q":"dependable legal research, document analysis, drafting, workflow automation"},{"t":"Proven litigation workflows","m":["ChatGPT","Gemini","Claude","Grok"],"q":"proven skills (deposition prep, doc review, research memos) that litigators actually rely on"}],"gap":[],"fix":[{"t":"Expensive ecosystem dependence","m":["ChatGPT","Claude","Gemini","Grok"],"q":"Expensive and ecosystem-dependent"},{"t":"Poor fit outside Thomson Reuters","m":["ChatGPT","Gemini","Grok"],"q":"less flexible for non-research workflows or teams outside TR stack."},{"t":"Weaker transactional drafting","m":["Claude","Grok"],"q":"weaker than Harvey on transactional drafting and firm-knowledge workflows."}]},"entries":[{"slug":"best-ai-legal-assistant","title":"Best AI legal assistant","rank":1,"of":8,"score":18,"appearances":4,"modelRanks":{"ChatGPT":1,"Claude":2,"Gemini":1,"Grok":2},"reason":"Best overall balance of dependable legal research, document analysis, drafting, workflow automation, and Microsoft 365/DMS integration, grounded in Westlaw and Practical Law; near-tied with Lexis+ with Protégé, but its mature task coverage gives it the edge for a typical mixed-practice team.","reasons":[{"model":"ChatGPT","reason":"Best overall balance of dependable legal research, document analysis, drafting, workflow automation, and Microsoft 365/DMS integration, grounded in Westlaw and Practical Law; near-tied with Lexis+ with Protégé, but its mature task coverage gives it the edge for a typical mixed-practice team."},{"model":"Gemini","reason":"Deeply integrated with Thomson Reuters' authoritative Westlaw database, delivering highly reliable, citation-backed legal research, deposition prep, and document analysis with minimal hallucinations for typical litigation practices."},{"model":"Claude","reason":"Thomson Reuters' assistant is the most trustworthy on the answer itself — grounded in Westlaw and Practical Law so citations check out, with proven skills (deposition prep, doc review, research memos) that litigators actually rely on; near-tie with Harvey for firms already inside the TR ecosystem."},{"model":"Grok","reason":"Exceptional depth in legal research and document analysis grounded in Westlaw's authoritative corpus, KeyCite validation, Deep Research agents, and guided workflows; reliable for litigation and research-heavy users already in the ecosystem"}],"fixes":[{"model":"ChatGPT","fix":"Expensive and ecosystem-dependent; poor value if the team does not need Thomson Reuters content or broad enterprise workflows."},{"model":"Claude","fix":"Its value is chained to expensive Westlaw/Practical Law subscriptions stacking on top, and it's weaker than Harvey on transactional drafting and firm-knowledge workflows."},{"model":"Gemini","fix":"High cost and ecosystem lock-in make it prohibitively expensive for small or boutique practices not already using Westlaw."},{"model":"Grok","fix":"Best value requires full Westlaw subscription; less flexible for non-research workflows or teams outside TR stack."}],"updated":"2026-07-15","api":"https://modelsagree.com/api/v1/best/best-ai-legal-assistant.json"},{"slug":"best-ai-legal-assistant-for-law-firms","title":"Best AI legal assistant for law firms","rank":1,"of":7,"score":18,"appearances":4,"modelRanks":{"ChatGPT":1,"Claude":2,"Gemini":1,"Grok":2},"reason":"Best overall balance for a typical firm: strong research, drafting, document analysis, and deep-research workflows grounded in Westlaw and Practical Law, with readily verifiable sources; near-tied with Lexis+ where the firm already prefers Lexis","reasons":[{"model":"ChatGPT","reason":"Best overall balance for a typical firm: strong research, drafting, document analysis, and deep-research workflows grounded in Westlaw and Practical Law, with readily verifiable sources; near-tied with Lexis+ where the firm already prefers Lexis"},{"model":"Gemini","reason":"Anchored to Westlaw's industry-standard database, it delivers the most reliable primary law legal research, deposition preparation, and document review with verifiable, hallucination-resistant citations. This ranking assumes the practitioner requires deep primary law research; it is in a near-tie with Lexis+ AI, separated only by the user's preference for Westlaw's proprietary editorial content."},{"model":"Claude","reason":"Grounded in Westlaw's authoritative primary law and KeyCite so answers are citeable and defensible; excellent at legal research, document review, and deposition/timeline prep; mature (ex-Casetext) assistant with strong hallucination guardrails and trusted integration into existing firm workflows."},{"model":"Grok","reason":"Exceptional research grounded in Westlaw's authoritative database, citation verification, document review, and litigation workflows; reliable fiduciary-grade outputs ideal for typical law firm research and drafting needs."}],"fixes":[{"model":"ChatGPT","fix":"Expensive and most valuable only with the broader Thomson Reuters content ecosystem"},{"model":"Claude","fix":"Value is fully realized only inside the Westlaw/TR ecosystem, and it's a weaker general drafting/workflow builder than Harvey; pricing skews enterprise."},{"model":"Gemini","fix":"Extremely expensive and restricted to firms already heavily invested in the broader Thomson Reuters ecosystem, making it financially unviable for solo or small practitioners."},{"model":"Grok","fix":"Tightly tied to Thomson Reuters ecosystem (requires or pairs best with Westlaw); less flexible for non-research heavy or enterprise automation outside that stack."}],"updated":"2026-07-14","rank_history":{"days":["2026-06-25","2026-07-12","2026-07-13","2026-07-14"],"ranks":[2,2,1,2]},"api":"https://modelsagree.com/api/v1/best/best-ai-legal-assistant-for-law-firms.json"}],"page":"https://modelsagree.com/product/cocounsel","check":"https://modelsagree.com/check?q=CoCounsel","updated":"2026-08-10T18:18:45.051Z","attribution":"modelsagree.com, CC BY 4.0"}