Best AI Contract Review Tools for Lawyers (2026)

The best AI contract review tools for lawyers in 2026 are Gavel Exec, Spellbook, CoCounsel, Harvey, Legora, LegalOn, Ivo, GC AI, goHeather and StrongSuit. For contract review and redlining in Microsoft Word with a published price, Gavel Exec ($160 per user per month) is our pick. Large firms usually shortlist Harvey, Legora or CoCounsel, and larger in-house departments usually compare LegalOn and Ivo.

Key takeaways

• All ten tools work with Microsoft Word, but they differ on who builds the playbooks, whether terms are benchmarked against market data, and whether you can see a price before a sales call.
• Five publish a price: Gavel Exec ($160 per user per month), GC AI ($500 per month for one user), goHeather ($200 per month billed annually for one seat), StrongSuit ($249 per month) and CoCounsel Legal (from $551.85 per month for solo and small firms).
• Spellbook, Harvey, Legora, LegalOn and Ivo quote through a demo. Gavel customers report Spellbook quotes of about $350 per user per month.
• For confidential client documents, look for SOC 2 Type II, zero data retention with AI providers and a commitment not to train on your data. ABA Formal Opinion 512 sets out lawyers' duties when using generative AI.

Last checked October 28, 2026, from each vendor's website. Gavel publishes this guide and makes Gavel Exec; we've stated competitors' facts as their vendors publish them and noted where something wasn't found.

AI contract review tools compared

How we compared these tools

We compared each tool on six things a contract lawyer checks before buying: where it runs, how playbooks are built and maintained, whether it benchmarks terms against market data, how redlines come back, data security, and price and trial terms. We used each vendor's own website and announcements, retrieved on October 28, 2026, and marked anything we couldn't find as "not found."

1. Gavel Exec: best for contract review and redlining in Word

Best for: transactional attorneys and in-house teams who want playbook-based redlines in Word and a published price.

Gavel Exec is AI contract review and drafting software that runs inside Microsoft Word as an add-in and on the web. It applies your playbooks and precedent and returns priority-ranked redlines as tracked changes, margin comments and a list of missing terms, with the reasoning behind each change.

• Playbooks: start from built-in playbooks written by practicing attorneys, or generate rules from your checklists, spreadsheet playbooks or signed agreements; any lawyer can edit them.
• Benchmarking: on-market, off-market or missing for your jurisdiction, industry and company size.
• Web app: batch analysis and multi-document comparison.
• Security: SOC 2 Type II; Zero Data Retention agreements with AI model providers; no training on customer data.
• Price: $160 per user per month, or $1,740 per user per year, with 25 free queries per user and no credit card.
• Company: part of Relativity since June 2026; used by over 2,000 legal organizations in 28 countries.

Limits: built for transactional work, with no case-law research database, and native iManage or NetDocuments integration isn't available yet.

2. Spellbook: best Word-first suite for transactional volume

Best for: transactional lawyers at firms and in-house teams.

Spellbook calls itself "the #1 AI contract review platform for transactional lawyers." It runs in Word and offers Review, Draft, Ask, Playbooks, Compare to Market and Associate for multi-document work, plus Autonomous Contract Management (October 2026), a repository it positions as a CLM replacement. It's SOC 2 Type II compliant with zero data retention.

• Price: not published; quotes by seat count through a demo. Gavel customers report about $350 per user per month.
• Trial: 7 days.

Compare: Spellbook alternatives and Spellbook vs Gavel Exec.

3. CoCounsel: best for research and drafting from one vendor

Best for: firms on Westlaw and Practical Law.

CoCounsel is Thomson Reuters' AI assistant. CoCounsel for Microsoft Word covers contract review, drafting and playbook management with Practical Law contract playbooks, and the next-generation CoCounsel Legal became generally available in the US in August 2026. Thomson Reuters bought Noetica, a deal-term benchmarking platform, in February 2026, and its October 14, 2026 release notes say Noetica benchmarking is now live in the CoCounsel Legal web app in the United States.

• Price: Thomson Reuters lists CoCounsel Legal from $551.85 per month for solo and small firms, and larger firms contact sales.

Compare: CoCounsel vs Gavel Exec.

4. Harvey: best for large law firms

Best for: Am Law firms and large corporate legal teams.

Harvey describes itself as "legal AI tailored for leading law firms and corporate legal teams" and says 80% of Am Law 100 firms use it. It runs on the web with Word and Outlook add-ins, applies playbooks in Word, and stores up to 100,000 documents in each vault and reviews up to 10,000 at a time in a review table. It holds SOC 2 Type II and ISO 27001.

• Price: not published; demo first.

Compare: Harvey vs Gavel Exec.

5. Legora: best collaborative workspace for firms

Best for: law firms and in-house teams that want review, research and drafting in one platform.

Legora's Word add-in drafts, redlines and reviews inside the document. Its playbooks let you set starting positions and red lines, and Tabular Review runs questions across many documents. It holds SOC 2 Type II and ISO 27001.

• Price: not published; demo first.

Compare: Legora vs Gavel Exec.

6. LegalOn: best pre-built playbook library for in-house teams

Best for: in-house departments that want playbooks ready on day one.

LegalOn ships 135+ playbooks written by its attorneys, a Playbook Agent that builds playbooks from your templates and redlines, a repository (Vault), cross-document review and matter management. It works on the web and in Word and holds SOC 2 Type II, ISO 27001 and ISO 27017.

• Price: per seat, quoted through a demo.

Compare: LegalOn alternatives.

7. Ivo: best for enterprise contract portfolios

Best for: in-house teams at large companies.

Ivo is "an enterprise-grade AI contract intelligence platform for in-house legal and business teams." It redlines in Word or Google Docs, builds playbooks from your contracts with help from its legal engineering team, and analyzes your contract repository. Customers include Uber, Shopify and Atlassian.

• Price: not published; demo first.

Compare: Ivo alternatives.

8. GC AI: best for solo and fractional general counsel

Best for: in-house lawyers who want one assistant for contracts and day-to-day questions.

GC AI pairs a web app with a Word add-in and connects to Gmail, Slack, Google Drive and HubSpot. It offers four pre-built playbooks, and teams can write their own. It holds SOC 2 Type II and SOC 3.

• Price: $500 per month (Individual); Team on request. 14-day free trial, no credit card.

Compare: GC AI alternatives.

9. goHeather: best for businesses reviewing their own contracts

Best for: small and mid-sized businesses that review contracts without outside counsel.

goHeather describes itself as "contract AI for businesses and law firms." Its Word add-in reviews Word and PDF files against your playbook and redlines with tracked changes.

• Price: $400 per month, or $200 per month billed annually, for one seat; 7-day free trial, no credit card.

10. StrongSuit: best for litigators who also handle contracts

Best for: solo litigators and boutiques.

StrongSuit, formerly Callidus Legal AI, calls itself "the legal AI platform for litigators." It adds contract review and redlining through a Word add-in alongside case research and litigation drafting. We didn't find playbook features.

• Price: $249 per month (Individual); 5-day free trial.

What about ChatGPT, Claude and Copilot?

General-purpose assistants such as ChatGPT, Claude and Microsoft Copilot can rewrite a clause or summarize a contract. ChatGPT Business costs $25 per user per month, or $20 billed annually. Used as general chat tools, these assistants don't apply your firm's playbook, benchmark terms against market data or keep a negotiation history. Microsoft now also sells legal features: Copilot for Legal, generally available since October 15, 2026, reviews contracts against a playbook and proposes tracked-change redlines in Word for Microsoft 365 Copilot license holders. Before using any of them on client documents, check the plan's data retention terms against your confidentiality obligations.

Best picks by type of practice

• Solo and small transactional firms: Gavel Exec, for a published price and playbooks you control.
• Mid-sized firms: Gavel Exec or Spellbook for contract work; add CoCounsel if you need Westlaw research.
• Large firms: Harvey or Legora for firm-wide platforms.
• Small in-house teams: Gavel Exec for contract-heavy work, or GC AI for a general in-house assistant.
• Enterprise in-house departments: LegalOn or Ivo, especially if you need a repository.
• Businesses without in-house counsel: goHeather.

For contract-type guides, see AI contract review by practice area.

For comparisons by task, see the best AI contract redlining software, the best contract playbook software and contract benchmarking tools. For published prices across 17 tools, see AI contract review software pricing compared.

How to choose an AI contract review tool

1. Start from your contracts. List the agreement types you review most and test each tool on those.
2. Decide who maintains playbooks. Vendor-built libraries save setup time; self-serve playbooks track your own positions.
3. Check the redline format. Suggestions should arrive as tracked changes you can accept or reject in Word.
4. Ask whether you need market data. Benchmarking helps when counterparties argue about what's market.
5. Price the whole team, including seat minimums and contract length.
6. Run a real trial. Use an agreement you've already negotiated and compare the tool's redlines with what you sent.

Security and ethics

ABA Formal Opinion 512 (July 2024) says lawyers using generative AI must understand the tool's capabilities and limits, protect client confidentiality under Model Rule 1.6, and review the output. In practice, ask each vendor for:

• SOC 2 Type II or ISO 27001 certification
• Zero data retention agreements with its AI model providers
• A written commitment not to train models on your documents
• Where your data is hosted and how to delete it

Frequently asked questions

What is the best AI tool for contract review?

For contract review and redlining in Microsoft Word with a published price, Gavel Exec is our pick at $160 per user per month. Large firms usually compare Harvey, Legora and CoCounsel; larger in-house teams compare LegalOn and Ivo.

Can AI review contracts without a lawyer?

No. AI tools spot issues and propose redlines quickly, but a lawyer still needs to review the output and make the judgment calls, as ABA Formal Opinion 512 makes clear.

Is it safe to use AI on confidential contracts?

It can be, with the right vendor. Look for SOC 2 Type II, zero data retention with AI providers and no training on your data, and check your client's requirements.

Which AI contract review tools work in Microsoft Word?

All ten tools in this guide work with Word, either as an add-in or through Word support.

How much does AI contract review software cost?

Among the tools in this guide that publish prices, plans run from $160 per user per month (Gavel Exec) to $500 per month for one user (GC AI), and Thomson Reuters lists CoCounsel Legal from $551.85 per month for solo and small firms. Spellbook, Harvey, Legora, LegalOn and Ivo quote through a demo. Our AI contract review software pricing comparison lists published prices for 17 tools.

Is there a free AI contract review tool?

The dedicated tools in this guide are paid, but you can try them free: Gavel Exec gives each user 25 free queries with no credit card, GC AI offers 14 days, goHeather, LegalOn and Spellbook offer 7 days, and StrongSuit offers 5 days.

More comparisons: all Gavel comparisons, Spellbook alternatives, Ivo alternatives, LegalOn alternatives and GC AI alternatives.