CCoCounsel Legal

More than 1 million professionals in 107 countries use CoCounsel, according to Thomson Reuters, and in August 2026 the company rebuilt CoCounsel Legal on Anthropic’s Claude Agent SDK so it can move a lawyer from a legal question to a draft brief in one workflow. Its advantage over startups is content: every research answer is grounded in Westlaw and Practical Law, with citations a lawyer can open and check.

It is best for firms that already live in Westlaw and want agentic research, document review and drafting from the same vendor. The main point to plan for is commitment. Small-firm pricing is reported at about $784 per attorney a month on a 1-year term, contracts auto-renew and mid-term downgrades are not allowed. We rate it 8.7/10 on our scale, helped by a 4.8 rating from 113 G2 reviews. We have not used CoCounsel Legal ourselves; this review is based on Thomson Reuters’ announcements and help pages, reported configurator pricing and public reviews.

Usage Counts and a Tracked Small-Firm Price List

Thomson Reuters publishes more usage figures than most legal AI vendors, and third-party trackers have captured its small-firm price list.

The 1 million user figure covers all CoCounsel products, not just CoCounsel Legal, so treat it as a measure of Thomson Reuters’ reach rather than of this product alone. The more useful signal for a buyer is the G2 profile: 113 reviews at 4.8 is a large and positive sample for a legal AI tool, and the complaints are about speed and file size rather than wrong citations.

The Claude Agent SDK detail matters too. Thomson Reuters is pairing a frontier model’s agent tooling with its own editorial content and its own legal model for bulk review, rather than relying on one model for everything.

Research, Drafting and Workspaces Backed by Westlaw

CoCounsel Legal combines research, drafting, document analysis and matter workspaces in one product, with Westlaw and Practical Law content behind each step.

Deep Research

• Question: a lawyer asks a legal question and sets jurisdiction and scope.
• Plan: the agent writes a multi-step research plan and shows its reasoning as it works.
• Report: it returns a structured report with Westlaw and Practical Law citations.
• Verify: Deep Research Verify checks whether cited authority actually supports specific statements in the report.

From Research to Draft

Westlaw Brief Builder, released in August 2026, uses Deep Research, KeyCite and Practical Law to take a litigator from research to a first-draft brief. Thomson Reuters stresses that lawyers keep control of strategy and final decisions. For transactional work, the Drafting Agent in CoCounsel for Word drafts, edits and reviews agreements from plain-language instructions, using Practical Law content and the firm’s own documents and playbooks.

Bulk Review and Workspaces

Tabular Analysis reviews up to 10,000 documents against up to 100 questions and returns a filterable table. Workspaces hold a matter’s documents, precedents and institutional knowledge so context carries across tasks. Guided workflows cover jobs such as drafting a complaint, propounding and responding to discovery, and reviewing deposition transcripts. From October 2026, litigation teams can move reviewed evidence from Reveal into CoCounsel Legal without exporting and re-uploading.

Outside the US, the January 2026 UK launch brought Deep Research on Practical Law content, a combined Westlaw and Practical Law experience and integrations with Microsoft 365, document management systems and HighQ. Womble Bond Dickinson was the named UK customer. Thomson Reuters says the August 2026 generation will reach Canada, the UK and Australia later in 2026.

Online Configurator for Firms of Ten or Fewer

• Buy: firms of up to 10 attorneys can configure a plan online; larger firms go through sales.
• Connect: install the Word and Outlook add-ins and link Microsoft 365 and the firm’s document management system.
• Load context: create Workspaces for active matters and add firm playbooks for drafting.
• Train users: start with Deep Research and guided workflows before moving to Brief Builder.

Lawyers Still Verify and Own Every Filing

Lawyers frame the question, review the research plan, check citations and own every filing. G2 reviewers note that the tool does not always surface authority that cuts against a position, so adverse research still needs a human pass.

Configurator Pricing for Small Firms, Sales for Large

Thomson Reuters sells CoCounsel through an online configurator for small firms and through sales for larger ones. The figures below are for law firms of up to 10 attorneys, as reported by CostBench from the configurator on October 13, 2026.

A 2-year term is reported at 12% off the 1-year price. Contracts auto-renew, cancellation must reach Thomson Reuters before the renewal date and mid-term downgrades are not allowed, according to the same source. A free trial is available on request.

A Solo Litigator’s $9,408 Year

These scenarios use the reported configurator prices. Firm sizes are illustrative.

• A solo litigator on CoCounsel Legal, 1-year term: $784 a month comes to $9,408 a year.
• A 5-attorney firm on CoCounsel Legal: $47,040 a year on a 1-year term, or $38,220 a year on a 3-year term. The longer term saves $8,820 a year but commits the firm to $114,660 over three years.
• An 8-attorney transactional firm on Essentials: $34,560 a year on a 1-year term, or $28,080 a year on a 3-year term.

Other costs to plan for: the price varies by jurisdiction, so a firm needing several state libraries should configure its exact coverage; auto-renewal can lock in another term if nobody tracks the date; and firms that only need drafting may overpay for the full CoCounsel Legal tier when Essentials covers their work.

CoCounsel Legal Compared With Lexis+ with Protégé, Harvey, Legora and Clio Work

CoCounsel Legal’s direct rival is LexisNexis’s Protégé; Harvey and Legora compete as independent AI workspaces, and Clio Work targets smaller firms.

The choice between CoCounsel Legal and Protégé usually follows the research subscription a firm already holds. Against Harvey and Legora, CoCounsel’s edge is primary law content with a citator behind it; their edge is broader document work and, for Legora, consumption pricing. Small firms watching cost should price Clio Work alongside CoCounsel Essentials. See our guides to AI agents for law firms and research agents.

Westlaw Firms and Busy Litigators

• Westlaw firms: research answers are grounded in content you already trust, with KeyCite and Deep Research Verify for checking.
• Litigators: Brief Builder, discovery workflows and deposition review cover much of the litigation cycle, and Reveal users can move evidence in directly.
• Small firms that want a known price: the configurator gives firms of up to 10 attorneys a per-attorney price instead of a sales negotiation.
• Microsoft 365 shops: Word and Outlook add-ins and document management connections keep work in familiar tools.
• Teams handling large productions: Tabular Analysis handles up to 10,000 documents per collection.

Lexis+ Users and Month-to-Month Seekers

• Lexis+ subscribers: Protégé gives similar agentic research on the content you already pay for.
• Firms that want month-to-month terms: plans run on 1- to 3-year terms that auto-renew.
• Lawyers who only need contract drafting: CoCounsel Essentials or a Word-focused tool such as Spellbook costs less than the full tier.
• Plaintiff personal injury firms: specialists such as Supio and Eve focus on medical records, demands and intake.
• Firms outside the US that want the newest features now: the August 2026 release reached the US first, with Canada, the UK and Australia due later in 2026.

Auto-Renewal Dates and Choosing the Right Tier

• Contract terms: auto-renewal, cancellation before the renewal date and no mid-term downgrades are reported, so put the renewal date in the firm calendar.
• Tier choice: CoCounsel Legal costs more than twice as much as Essentials per attorney; buy the full tier only for lawyers who need Westlaw-grounded research.
• Speed and file size: G2 reviewers report slow responses with large documents and uploads that fail on very large files.
• Adverse authority: reviewers note the tool does not always surface sources that cut against a position.
• Model mix: Thomson Reuters names OpenAI GPT and Google Gemini models in some features and Anthropic’s Claude Agent SDK in the new release; ask which models touch your data and under what terms.
• Regional rollout: confirm which features are live in your jurisdiction before signing.

Brief Builder and a Drafting Agent in August 2026

• On August 20, 2026, Thomson Reuters released the next generation of CoCounsel Legal with Westlaw Brief Builder, Workspaces, a Drafting Agent in Word, Tabular Analysis and Deep Research Verify, built on Anthropic’s Claude Agent SDK.
• On January 26, 2026, CoCounsel Legal launched in the UK, with Deep Research on Practical Law and Tabular Analysis available in the US.
• On August 5, 2025, Thomson Reuters launched CoCounsel Legal with agentic Deep Research and the new Westlaw Advantage.

For Firms Already Paying for Westlaw, Yes

For firms already paying for Westlaw, yes. CoCounsel Legal scores 8.7/10 on our scale because it pairs real agentic behavior (research plans, brief drafting, bulk review of 10,000 documents) with citations to content lawyers already rely on and strong user ratings. Thomson Reuters’ scale also lowers vendor risk: 20,000 organizations had adopted CoCounsel by August 2025.

The areas Thomson Reuters could improve are commercial. At a reported $784 per attorney a month, a 5-lawyer firm spends $47,040 a year, and more flexible contract terms would make buying easier for small firms. Start with a trial, give the full tier only to lawyers who research daily, and compare the quote with Lexis+ with Protégé and Clio Work before committing to three years.

Per-Attorney Pricing Through the Configurator

How Much Does CoCounsel Legal Cost Per Attorney?

For law firms of up to 10 attorneys, Thomson Reuters’ configurator is reported at $784 per attorney a month for all-state and federal coverage on a 1-year term and $637 on a 3-year term. CoCounsel Essentials is reported at $360 a month. Larger firms get a custom quote.

What Is the Difference Between CoCounsel Legal and CoCounsel Essentials?

CoCounsel Legal adds Westlaw-grounded Deep Research, Brief Builder, Tabular Analysis and the full set of agentic workflows. Essentials covers CoCounsel’s core drafting and analysis tools at less than half the price.

Does Thomson Reuters Use My Documents to Train CoCounsel?

Thomson Reuters’ security FAQ says user content, prompts and AI outputs are not used to train CoCounsel or third-party models. Usage information is used to improve the product, and data is encrypted at rest and in transit.

Is CoCounsel Legal Better Than Lexis+ with Protégé?

Both offer agentic research grounded in their own content and citators, so the answer usually depends on whether your firm relies on Westlaw or Lexis. CoCounsel publishes small-firm prices through its configurator; Protégé is quote-based and requires a Lexis+ subscription.

Can CoCounsel Legal File or Finalize Work on Its Own?

No. It plans research, drafts briefs and agreements and reviews documents, but lawyers keep control of strategy and sign off on every output. Reviewers also advise checking answers and looking separately for adverse authority.