CoCounsel Legal
Thomson Reuters' legal AI grounded in Westlaw and Practical Law
Overview
CoCounsel began as Casetext's GPT-4 legal assistant in March 2023; Thomson Reuters bought Casetext for $650M in August 2023. Today's CoCounsel Legal (formerly listed as CoCounsel), rebuilt on Anthropic's Claude Agent SDK, handles research, document analysis and drafting grounded in Westlaw and Practical Law.
Pricing
Pricing shown for reference only. These figures reflect RECATOOLS research as of 14 Oct 2026 and may be out of date or incomplete. This is not financial or purchasing advice — always confirm the current price on the provider’s official website before making any decision.
Use cases
What you can produce with CoCounsel Legal
- A fully cited Deep Research report grounded in Westlaw and Practical Law from a plain-language legal question
- Up to 100 questions run across as many as 10,000 documents, returned as one sortable table footnoted to sources
- Facts extracted and issues flagged from complaints, discovery or contracts by the Litigation Document Analyzer, linked to the exact page
- A litigation brief built with Westlaw Brief Builder, from issue framing to argument structure, with authority attached
- Drafts and redlines in Microsoft Word against a firm's standard using Practical Law model language
- Matter Workspaces that keep documents and history so later requests reuse that context
- Deposition outlines and contract-playbook reviews (CoCounsel Essentials features)
CoCounsel Legal is Thomson Reuters' AI layer over Westlaw and Practical Law: it plans multi-step research, reviews large document sets and drafts in Word, with linked citations to check. An earlier version posted the highest average in the Vals legal AI benchmark of February 2025. It fits firms and legal departments that already pay for Westlaw.
Caveats: prices are quote-based, and the third-party figures available start near $300 a month for the entry plan. The rebuilt version launched in the US first. In Southeast Asia, Thomson Reuters offers it with UK, US and Australian content and local support, but claims no Singapore or Malaysian law content, so firms relying on local statutes should test that gap first.
What we found
CoCounsel started as Casetext's GPT-4 legal assistant in March 2023. Thomson Reuters closed its $650 million cash purchase of Casetext that August, and the product, formerly listed here simply as CoCounsel, is now CoCounsel Legal, sold alongside Westlaw and Practical Law. A rebuilt version, which Thomson Reuters says runs on Anthropic's Claude Agent SDK, became available in the US in August 2026, with Canada, the UK and Australia promised later in the year. It plans multi-step research, analysis and drafting from one plain-language request and links each citation back to its source.
The strongest outside evidence is the Vals Legal AI Report of February 2025. CoCounsel averaged 79.5% across the four tasks it entered, the highest average in that study. It beat the lawyer baseline on document Q&A, summarisation and data extraction, but trailed it on chronology generation, 78% against 80.2%. That test covered an earlier CoCounsel, not the current agentic rebuild.
The fullest published hands-on review appeared in the ABA's GPSolo magazine in February 2026. Jeffrey M. Allen and Ashley Hallene reported no hallucinations during their testing and concluded that CoCounsel makes sense for firms already using Westlaw, while others should check whether the cost outweighs the benefit. The article discloses that Thomson Reuters sponsors the ABA division that publishes it and that the authors received free access. It quoted starting prices of $292.50 a month for CoCounsel Essentials, $415.35 for Westlaw Advantage with CoCounsel Essentials and $551.85 for CoCounsel Legal. Thomson Reuters' own pricing pages refused our requests, so we could not confirm current figures.
For ASEAN readers, Thomson Reuters extended CoCounsel to Southeast Asia in March 2025 and runs a Singapore product page offering local support. That page describes research grounded in UK, US and Australian content, not Singapore or Malaysian law. Firms whose work turns on local statutes should test that gap before signing. Firms already paying for Westlaw get the most from it.
Compiled by RECATOOLS from public sources: vendor documentation and pricing, code repositories and published reporting.
About this listing
This entry was compiled from publicly available data including CoCounsel Legal's official website, press releases, documentation, and reputable third-party publications. RECATOOLS is not affiliated with CoCounsel Legal unless explicitly stated.
Third-party AI tools update their pricing, features, availability, and policies frequently. Information here may be outdated by the time you read this — we make reasonable efforts to keep listings current, but cannot guarantee absolute accuracy.
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