CoCounsel

CoCounsel is the legal AI assistant from Thomson Reuters, the company behind Westlaw and Practical Law. It started life at Casetext, which Thomson Reuters bought in 2023 for US$650 million, and the Casetext name has now gone. You ask a legal question in plain English and it researches, analyses and drafts, citing Westlaw cases and Practical Law guidance with links. It can review thousands of documents against a list of questions, draft briefs, and works inside Word, Outlook and Teams. There is also an official MCP connection so Claude can use it.

Pick CoCounsel if your lawyers already pay for Westlaw and want AI answers grounded in trusted case law with citations they can click. Harvey is the broader platform at big firms and is stronger on bulk diligence workflows. Spellbook is cheaper and simpler for contract drafting in Word. General chat assistants like Claude and ChatGPT are fine for drafting but do not have Westlaw's case law behind them.

The catch is that it is tied to the Thomson Reuters ecosystem. Pricing is by quote and usually bundled with Westlaw, the product tiers are confusing, and it is built mainly for US law. It is less useful in Australia or the UK unless you mostly need document review and drafting.

• Litigators
• Law firms
• In-house legal teams
• Government legal teams

Law firms and legal teams, mostly in the US, that already use Westlaw or Practical Law.

• Research with citations

  Ask a question in plain English and get an answer drawn from Westlaw and Practical Law, with linked citations.

• Deep research and agent steps

  For bigger questions it makes a plan, works through each step and shows you how it got there.

• Tabular document review

  Review up to 10,000 documents against up to 100 questions and get the answers in a table.

• Brief and document drafting

  Drafts briefs, memos and letters, with a Westlaw Brief Builder for litigation.

• Works where lawyers work

  Add-ins for Word, Outlook and Teams, plus saved matter workspaces.

• CoCounsel Essentials

  Custom

  Firms adding AI to an existing Westlaw or Practical Law plan.

  • Bundled with Westlaw or Practical Law
  • Core research, drafting and document Q&A
• Our pick

  CoCounsel Legal

  Custom

  Teams that want the full research, review and drafting set.

  • Deep research and agent workflows
  • Bulk tabular document review
  • Word, Outlook and Teams add-ins

Prices in USD unless noted, checked 22 October 2026. Vendors change plans often, so confirm on their site before you buy.

Ways CoCounsel can slot into your week.

1. 1

   Research a legal question

   Ask about a point of law and get a sourced answer with Westlaw cases to read, then confirm the key authorities yourself.

2. 2

   Review a discovery set

   Run thousands of documents against a list of questions and get a table of answers with links to each source.

3. 3

   Summarise depositions and contracts

   Turn long transcripts or agreements into short summaries before a meeting or hearing.

4. 4

   Draft a brief

   Build a first draft of a litigation brief, with citations to check and edit.

It fits best where Westlaw and Practical Law are already the research tools. It plugs into Word, Outlook and Teams, and Claude users can connect to it through its MCP server.

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