CoCounsel
Agentic legal AI grounded in Westlaw and Practical Law.
About
CoCounsel is Thomson Reuters' flagship AI legal assistant, descended from the product Casetext launched in 2023 as the first AI legal assistant of its kind. The next generation, now in early access with general availability planned for August 2026 in the US, moves beyond discrete skills toward agentic workflows: a lawyer describes a matter in plain language, and the system drafts a plan, works through the legal issues, pulls from the firm's own precedents alongside Westlaw and Practical Law, and produces cited, iterable work product.
The headline capabilities include Westlaw Brief Builder for first-draft briefs with validated authority, a Drafting Agent inside Microsoft Word, Workspaces that preserve matter context across teams, Tabular Analysis that reviews up to 10,000 documents against up to 100 questions, and Deep Research Verify, which checks whether cited authority actually supports the assertions made. It is powered in part by Thomson, the company's proprietary legal-focused large language model. Thomson Reuters says one million professionals across 107 countries now use CoCounsel technology.
Pricing reflects the enterprise legal market: third-party comparisons put CoCounsel Legal near $1,695 per month with a lighter Essentials tier around $341. The core differentiator is citation grounding in Westlaw's verified database, which reduces hallucination risk on US case law where citation accuracy is professionally critical. Like every AI legal tool, its output still requires lawyer review before it goes anywhere near a client or a court.
What it can do
- Deep Research with agentic guided workflows
- Westlaw Brief Builder with authority validation
- Drafting Agent inside Microsoft Word
- Tabular Analysis across up to 10,000 documents
- Deep Research Verify for citation support checks
- Matter Workspaces combining firm documents and precedents
Setup
- Contact Thomson Reuters sales or buy an eligible plan online.
- Provision users and connect firm document repositories and precedents.
- Set up Workspaces per matter for persistent context.
- Use Brief Builder, Drafting Agent and Tabular Analysis on live matters.
- Verify all citations and outputs with attorney review before reliance.
Prerequisites
Thomson Reuters CoCounsel license (enterprise legal pricing); attorney review of all AI output.
Use cases
Works with
Trust score — 8/10
Scored 8/10 (verified tier, metrics-v1). Evidence: next-gen launch with Deep Research and agentic workflows reported by LawSites (lawnext.com, June 2026); 1M+ professionals across 107 countries (Thomson Reuters via advfn.com, May 2026); pricing ~$1,695/mo Legal / ~$341 Essentials (strongsuit.com comparison). Strengths: Westlaw-grounded citations reduce hallucination risk, strong beta reception, incumbent distribution. Docked for: (1) next-gen GA not until Aug 2026 US; (2) pricing is steep and third-party-reported, not published by TR. License: proprietary commercial SaaS.
How the trust score is built
Full methodology →- Adoption · stars/downloads, log-scaled vs peers
- 8.0/10
- Maintenance · recency, releases, issue load
- 8.0/10
- Openness · license + docs
- 6.0/10
- Manual review · sanity read + red-flag check
- 8.0/10
- · Next-gen CoCounsel Legal with Deep Research + agentic workflows, early access, GA planned Aug 2026 US (LawSites, lawnext.com)
- · 1M+ professionals across 107 countries use CoCounsel tech (Thomson Reuters PR via advfn.com, May 2026)
- · Pricing ~$1,695/mo CoCounsel Legal, ~$341/mo Essentials per third-party comparison (strongsuit.com)
- · Westlaw Brief Builder, Tabular Analysis (10k docs / 100 questions), Deep Research Verify (TR press release)
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.