CoCounsel vs Lexis+ with Protégé (formerly Lexis+ AI): 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.

Lexis+ with Protégé is LexisNexis Legal & Professional’s legal AI workflow product, formerly called Lexis+ AI. LexisNexis says Lexis+ AI debuted in October 2023 as a generative legal research platform, followed by a second-generation release in April 2024. Protégé became generally available in the United States in January 2025, and the product was renamed Lexis+ with Protégé in February 2026. It serves law firms, corporate legal departments, government agencies, law schools, and individual legal professionals. Its central distinction is grounding responses in LexisNexis legal content, including Shepard’s citation data, while permitting approved use of a firm’s documents and work product. The product connects research with drafting, review, and matter-focused tasks.

A typical session starts with a conversational legal question, an uploaded pleading or contract, or a drafting request. The platform can search authoritative content, summarize a document, draft a motion or transaction document, suggest follow-up actions, and connect quotations to source material for checking. Protégé can recommend actions based on an uploaded file, generate timelines, draft deposition questions and discovery requests, and support Deep Research for complex issues. With explicit permission, it can draw on a document-management system and store large collections in Protégé Vault. Microsoft Word users can continue editing through Lexis Create+. Human review remains necessary, particularly for citations, facts, legal judgment, confidentiality, and final drafting decisions. Output quality also depends on the prompt, source material, and selected model.

The main tradeoff is authority and workflow integration against a less transparent buying process and the need for attorney verification. Lexis+ with Protégé competes most directly with Thomson Reuters CoCounsel Legal, vLex Vincent AI, and Harvey. CoCounsel Legal combines Westlaw and Practical Law content with research, analysis, and drafting. Vincent AI focuses on vLex content and multilingual legal work, while Harvey supports professional services workflows across research, drafting, and analysis. LexisNexis emphasizes model choice, Shepard’s checking, customer-controlled personalization, and encrypted handling, but it does not publish a simple self-serve price or a complete model-performance benchmark. Choose it when LexisNexis content, citation validation, document work, and firm controls matter more than transparent pricing.