Description
CoCounsel is Thomson Reuters’ generative AI legal assistant, built to unify legal research, drafting, and document analysis in one experience. It’s grounded in Thomson Reuters’ own legal content, including Westlaw case law and Practical Law guidance, and offered across four tiers: standalone CoCounsel Essentials, Westlaw Advantage with CoCounsel Essentials, Practical Law Dynamic Tool Set with CoCounsel Essentials, and the full CoCounsel Legal bundle. Features include end-to-end agentic workflows, a Deep Research mode that builds multi-step research plans, and an expert-built prompt library. CoCounsel works through the web and inside Microsoft Word, Outlook, and Teams. It suits law firms and in-house legal teams, especially litigation-heavy practices already invested in the Westlaw and Practical Law ecosystem.
Key Features
- Deep Research — an agentic AI mode that builds and executes multi-step legal research plans.
- Agentic workflows — end-to-end automation for multistep legal tasks rather than single-prompt answers.
- Grounded in Westlaw and Practical Law — research and drafting answers are tied to Thomson Reuters’ own legal content.
- Expert-built prompt library — pre-written prompts covering common legal research and drafting tasks.
- Document analysis and drafting — contract review, drafting support, and litigation preparation.
- Microsoft 365 integration — works inside Word, Outlook, and Teams depending on plan.
How It Works
A user asks a legal question or assigns a task in plain language, and CoCounsel either answers directly or, for more complex requests, plans out and executes a multi-step research or drafting workflow through Deep Research. Answers are grounded in Thomson Reuters’ proprietary content: Westlaw for case law and statutes, Practical Law for practice guidance and templates. Because CoCounsel is licensed in tiers, what a firm can actually do with it depends heavily on which product it’s bundled with — CoCounsel Essentials alone provides the AI assistant without full Westlaw case law search, while the Westlaw Advantage and Practical Law bundles add full research or guidance access on top. The expert-built prompt library gives new users starting points for common tasks like summarizing a deposition or drafting a first-pass clause, and results can be exported directly into Word, Outlook, or Teams documents.
Technical Architecture & Overview
- Core Engine: Generative AI grounded in Thomson Reuters’ proprietary legal content (Westlaw, Practical Law); the underlying foundation model isn’t officially specified on Thomson Reuters’ pricing pages.
- Deployment: Cloud-based web platform; also available inside Microsoft Word, Outlook, and Teams.
- API Surface: Integrates with Thomson Reuters’ own tools (Westlaw, Practical Law, HighQ) and Microsoft 365; no public third-party developer API documented for CoCounsel itself.
- Known Limits: Full case law research requires the Westlaw Advantage bundle, not CoCounsel Essentials alone; online self-serve pricing only applies to firms with up to 10 attorneys, and even then requires entering firm details into a configurator rather than seeing a flat number upfront.
Pros & Cons
| Pros | Cons |
|---|---|
| Answers are grounded in Thomson Reuters’ own trusted legal content, not just a general-purpose model | No flat published price; even the online configurator requires entering firm details, and it only covers firms up to 10 attorneys |
| Deep Research handles genuinely multi-step legal research rather than single-shot answers | Full value requires bundling with Westlaw or Practical Law, which adds significant cost on top of CoCounsel Essentials alone |
| Works directly inside Word, Outlook, and Teams, fitting into an existing workflow | Firms outside the Thomson Reuters ecosystem face steep total cost compared to standalone AI legal tools |
| 2-year and 3-year terms offer real discounts over 1-year pricing | New features are locked to plan tier during the contract term; existing customers must contact sales rather than self-serve online |
Our Take
CoCounsel’s real value only shows up once it’s bundled with Westlaw or Practical Law — on its own, CoCounsel Essentials is a capable AI assistant, but the case law research firms actually need lives in the bundled tiers. For a firm already paying for Westlaw, adding CoCounsel is often cheaper than it looks, since Thomson Reuters prices the bundle below what the pieces cost separately.
Not ideal for: firms with no existing Thomson Reuters subscription — buying the full CoCounsel Legal bundle from scratch is a much bigger commitment than a standalone legal AI tool, and the online configurator itself tops out at 10 attorneys before requiring a sales call anyway.
Pricing
Thomson Reuters does not publish a flat price for CoCounsel. Firms with up to 10 attorneys can use an online configurator on Thomson Reuters’ own site to get a quote after entering sector, attorney count, and jurisdiction; larger firms and existing customers must contact sales directly. Four tiers are available: CoCounsel Essentials (standalone), Westlaw Advantage with CoCounsel Essentials, Practical Law Dynamic Tool Set with CoCounsel Essentials, and the full CoCounsel Legal bundle. Longer 2-year and 3-year terms carry a meaningful discount over 1-year pricing.
https://sales.legalsolutions.thomsonreuters.com/en-us/products/cocounsel-legal/700/plans-pricing
Last verified: August 18, 2026
Platform Availability
Web | Microsoft Word | Outlook | Teams
Best For
Law firms | In-house legal teams | Litigators | Existing Westlaw and Practical Law customers
Frequently Asked Questions
Does CoCounsel publish pricing?
Not as a flat number. Firms with up to 10 attorneys can use an online configurator after entering firm details; larger firms and existing customers must contact Thomson Reuters sales directly.
Does CoCounsel include Westlaw case law research?
Only if bundled with Westlaw Advantage. CoCounsel Essentials alone is the AI assistant without full case law search; the Westlaw Advantage and CoCounsel Legal bundles add that access.
What is Deep Research in CoCounsel?
Deep Research is CoCounsel’s agentic mode that plans and executes multi-step legal research tasks automatically, rather than answering a single prompt at a time.
Can I use CoCounsel inside Microsoft Word?
Yes. CoCounsel is available through the web and inside Microsoft Word, Outlook, and Teams, depending on the specific product setup.
How does CoCounsel differ from Harvey?
CoCounsel is grounded in Thomson Reuters’ own Westlaw and Practical Law content with tiered, semi-transparent pricing for smaller firms, while Harvey is a broader enterprise legal AI platform sold entirely through custom sales with no self-serve pricing at any firm size.
