Overview
What is CoCounsel Legal?
CoCounsel Legal is Thomson Reuters' flagship AI legal assistant, built to work at the level of a senior associate. Describe a matter in plain language and it builds a step-by-step plan, researches, analyses, and drafts polished, cited work product – no prompt engineering needed. It's the only legal AI grounded in authoritative Westlaw primary law, Practical Law expert guidance, and a firm's own documents, with every step of its reasoning visible and every citation linked for verification. Originally launched as Casetext's CoCounsel in 2023 and acquired by Thomson Reuters for $650M, it now serves over 1 million users across 100+ countries. CoCounsel Legal works inside Microsoft Word, Outlook, and Teams, connects to iManage, NetDocuments, SharePoint, and Box, and is SOC 2 and ISO 42001 certified with no AI training on customer data. A 2026 Forrester study found a 33% average reduction in time spent on research, review, and drafting.
Capabilities
CoCounsel Legal features
Legal research
Document analysis
Drafting
Single prompt task execution
Native access to Westlaw and Practical Law
Explains reasoning and shows sources used
Workspaces
Brief Builder
Firm and organizational intelligence
Web Search
Connects with Microsoft 365, HighQ, iManage, NetDocuments, SharePoint, Icertis, DeepJudge, Supio, and Smokeball
Deep dive
More about CoCounsel Legal
CoCounsel Legal Features
- Agentic AI Workflows (Plan, Execute & Deliver from One Prompt)
- Deep Research (Westlaw-Grounded Legal Research)
- Litigation Document Analyzer
- Westlaw Brief Builder
- Tabular Analysis (Up to 10,000 Documents × 100 Questions)
- Workspaces (Matter Context, Documents & History)
- Search & Summarize Practical Law
- Draft & Modify Clauses
- Contract Playbooks & Policy Compliance
- Summarize, Review & Compare Documents
- Prepare for a Deposition
- Timeline Builder
Do's and Don't
Do:
- Request a free demo or trial and test it on your own documents.
- Use the online configurator if you have 10 or fewer attorneys.
- Pick a 2- or 3-year term to save around 12–18%.
- Choose the bundle that matches your practice – litigation (Westlaw) or transactional (Practical Law).
- Click through every citation to verify before filing.
- Use Workspaces to keep matter context across sessions.
Don't:
- Don't buy Essentials expecting research – it has no Westlaw content.
- Don't forget the Westlaw cost – full research needs the bundled plans.
- Don't expect a free tier – trials are short and sales-gated.
- Don't assume online prices apply to existing customers – they must contact sales.
- Don't treat AI output as final – attorney review is required.
Key Use Cases
- Litigation: deep research, brief building, and document analysis grounded in Westlaw.
- Transactional: contract review, clause drafting, and playbooks with Practical Law guidance.
- Due diligence: review thousands of documents against dozens of questions in one table.
- Deposition prep: build timelines and prepare questions from case files.
- In-house teams: cut outside counsel spend by handling routine research and drafting internally.
- Firms on Microsoft 365: research and draft without leaving Word, Outlook, or Teams.
The verdict
Pros & cons
Pros
Only AI grounded in Westlaw and Practical Law – trusted, verifiable sources.
Transparent step-by-step reasoning with linked citations.
Handles research, analysis, and drafting from a single prompt.
Works natively inside Word, Outlook, and Teams.
Broad document management integrations.
Self-serve online pricing for small firms – no sales call needed.
New features included during your contract term at no extra cost.
Won multiple 2026 industry awards (ILTA, AALL, NLJ, The Recorder).
Cons
Expensive once Westlaw content is included – often $300–600+ per user/month all-in.
Pricing varies widely by jurisdiction and term.
Essentials alone lacks legal research content.
Annual or multi-year commitment required.
Online pricing limited to 10 attorneys and new customers.
Full value depends on being in the Thomson Reuters ecosystem.