CoCounsel vs Spellbook: 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.

Spellbook is a contract AI suite made by Dialog Enterprises Inc., a Canada-based company that operates under the Spellbook name. The company says its first generative contract review tool launched in 2022, and its current website says more than 5,000 legal teams use the product. Its October 2025 funding announcement reported 4,000 law firms and in-house legal teams in 80 countries, while the current site reports more than 5,000 teams. The company’s product focus is transactional work: drafting agreements, reviewing terms, applying redlines, and keeping positions consistent across a deal. Spellbook is therefore aimed at commercial legal teams rather than users seeking a general legal chatbot or a dedicated case-law research database.

A normal Spellbook workflow starts with a contract or intake request and keeps the lawyer in the review loop. The product can pull contracts from email and Slack, run a first-pass review against team standards, draft clauses or full agreements, and produce tracked redlines in Word. Review, Draft, Ask, Benchmarks, and Playbooks cover the Word add-in workflow. Playbooks turn recurring instructions into reusable review checklists, while Library and Repository features make precedents and signed agreements searchable. Associate is a multi-document agent for transactional matters that works under attorney oversight. Spellbook also lists integrations with Google Docs, OneDrive, Dropbox, SharePoint, Google Drive, and iManage. The lawyer remains responsible for checking suggested language and deciding which changes to accept.

Spellbook’s contract focus is useful for lawyers who work in Word and apply repeatable review standards, but it limits the product’s role. Harvey overlaps on AI-assisted legal drafting and analysis, while Ironclad overlaps more closely on contract operations, repository management, and lifecycle workflows. LawGeex is another contract-review alternative. Spellbook publishes no dollar price, requires attorney oversight, and does not present itself as a substitute for legal judgment. Its public pages also do not establish a self-hosted deployment or a public developer API. Choose Spellbook if your team drafts and negotiates commercial contracts and wants Word-based review with reusable playbooks. Choose a broader legal research or contract-lifecycle product when those functions matter more than Word-native review.