CoCounsel vs Luminance: pricing, features and which to choose

CoCounsel is a professional legal AI assistant made by Thomson Reuters and descended from Casetext's product of the same name. Casetext launched CoCounsel in March 2023, and Thomson Reuters announced a $650 million acquisition of Casetext that year. The product now sits across Thomson Reuters' legal portfolio rather than operating as an independent Casetext service. Thomson Reuters said in February 2026 that one million professionals across 107 countries and territories had chosen CoCounsel across legal, tax, audit, compliance, and related products. Legal users are the clearest audience, including litigators, transactional lawyers, in-house teams, and firms that already buy Westlaw or Practical Law. The acquisition brought Casetext's product expertise into Thomson Reuters, while the current offering adds licensed content and broader distribution.

A typical workflow starts with a natural-language request, an uploaded file, a connected document repository, or a Thomson Reuters research collection. Users can summarize and compare documents, extract information, identify missing provisions, prepare deposition materials, build timelines, draft text, and check contract policies. Knowledge Search can find material in a firm's own repositories, while Browse Library exposes expert-built prompts and skills. Agentic workflows handle multi-step assignments, and Deep Research gathers and synthesizes authority for a more complete answer. Outputs are designed to include citations or links where selected content supports them, but lawyers still need to check quotations, authorities, privilege, confidentiality, and final work product before relying on it. The system assists legal judgment rather than replacing professional review.

CoCounsel's strongest case is a research-heavy practice already invested in Thomson Reuters content. Its citations, document skills, repository connections, Microsoft 365 integrations, and agentic workflows can reduce switching between research and drafting tools, though outputs remain subject to legal review. Law firms should compare it with Harvey, Lexis+ AI, and Legora rather than assume the content advantage settles the decision. Independent 2025 benchmarking placed CoCounsel among the stronger tools across document tasks, while Law360 reported that some early adopters preferred Harvey or Legora for interface and workflow reasons. Privacy terms prohibit using customer prompts and content to train third-party models, with configurable retention, encryption, and zero-retention model APIs. Choose CoCounsel when Westlaw or Practical Law is central and authoritative citations matter most.

Luminance is a Cambridge-born legal technology company founded in 2015 and launched commercially in 2016. Its platform applies specialist artificial intelligence to contracts and related legal work for enterprise legal departments, law firms, procurement teams, sales groups, finance functions, and compliance staff. The company’s About page reports more than 1,000 enterprise customers across over 70 countries and more than 220 million legally verified documents informing its AI. Its February 2025 funding announcement reported a $75 million Series C led by Point72 Private Investments, bringing total funding to $165 million. Luminance is designed for organisations managing substantial agreement portfolios, rather than consumers seeking an inexpensive general legal chatbot or casual question answering service.

A typical workflow begins when users import agreements from local files or connected repositories. The Repository helps teams organise documents, search across clauses, extract structured terms, identify risks, and examine obligations. Negotiation compares proposed language with an organisation’s preferred positions, supports redlining, and records relevant context. Other workflows address drafting, post-execution monitoring, compliance, investigation, and collaboration. Luminance also markets Lumi, specialist agents, and Lumi Go, which allows a customer to send a draft agreement to a counterparty for AI-assisted negotiation. The platform supports work beyond Legal by presenting contractual information to procurement, sales, finance, and executive teams. Human review remains necessary for legal judgments, business decisions, approvals, and final contract execution.

Luminance’s enterprise focus, negotiated procurement, and dependence on contract context make it a poor fit for casual legal questions or teams requiring transparent self-serve pricing. CoCounsel and Lexis+ with Protégé are broader comparisons for legal research, analysis, drafting, and question answering connected to large legal information services. Legora is a closer workspace competitor for law firms and in-house legal teams seeking integrated drafting, research, collaboration, and agent workflows. Luminance is strongest when the central problem is a large corporate contract portfolio spanning review, negotiation, repository analysis, and obligations. Choose it when governance, portfolio intelligence, and controlled model selection matter more than a public price, an open developer platform, or a general legal research assistant.