ChatGPT alternatives for contract review: 7 legal AI tools compared

ChatGPT alternatives at a glance

The table sets ChatGPT beside seven legal AI tools: where each runs, what it adds for contract work, what it costs and how you can try it.

Why lawyers look for ChatGPT alternatives

ChatGPT is often a lawyer's first AI tool for contracts, and it handles the language work well: a plain-English summary for a client, a cleaner clause, an explanation of an unfamiliar provision. Lawyers who review contracts every week usually look further for three reasons.

• Consistency. ChatGPT can hold your positions on liability caps, indemnities and governing law in custom instructions or a project's instructions and files, but OpenAI's help center describes no legal playbook feature that checks each clause against your standard position and fallbacks.
• The markup. Counterparties expect tracked changes in Word. LawNext described ChatGPT for Word as letting lawyers "proofread, get suggested edits, and flag formatting issues," and neither OpenAI's help article nor its release notes say that edits arrive as tracked changes.
• Client data. OpenAI's no-training default covers Business, Enterprise and Edu. Its pricing page lists training on Free, Go, Plus and Pro content as opt-out, so a lawyer on a personal plan has to turn it off before uploading client documents.

How legal AI differs from ChatGPT for contract review

Legal AI tools save your negotiating positions as a playbook, apply them to the whole agreement and return tracked changes in Word, often with market data or legal sources behind each edit. ChatGPT is a general assistant working from your prompt, attachments and any project instructions and files. It's strong at drafting, summarizing and explaining, and less consistent at applying the same positions to every contract.

• Playbooks. A playbook records your standard position and fallbacks for each clause. Gavel Exec, Spellbook, CoCounsel, GC AI and Copilot for Legal review against one, and Anthropic publishes playbook-aware contract plugins for Claude. ChatGPT has no legal playbook feature, though Projects and custom instructions can hold your positions and reference files.
• Redlines across the whole agreement. Gavel Exec marks up the entire agreement as tracked changes and explains each edit, and Copilot for Legal, Claude for Word and Spellbook also write tracked changes. ChatGPT for Word drafts from notes, summarizes, revises selected text and adjusts headings and formatting in the open document (see can ChatGPT redline a contract).
• Market data and legal sources. Gavel Exec labels provisions on-market, off-market or missing by jurisdiction, industry and company size, Spellbook compares contracts with industry standards, and CoCounsel answers from Westlaw and Practical Law.

1. Gavel Exec: best for turning contract prompts into a playbook applied in Word

Best for: lawyers who review the other side's paper every week and want the positions they keep in ChatGPT prompts or custom instructions turned into a playbook, with no sales call to start.

Gavel Exec is AI contract review and drafting software that runs inside Microsoft Word as an add-in and on the web. It redlines the full agreement as tracked changes ranked by priority, explains each change, adds margin comments and lists missing terms. At MIA Contract Lawyers, Martin Algie cut first-cut review from about 15 hours to about 5 hours per contract.

• Playbooks: start from built-in playbooks written by practicing attorneys, or generate rules from your checklist, spreadsheet playbook or signed agreements (.docx, PDF or .csv), and share them read-only or with edit access.
• Benchmarking: the web app labels each provision on-market, off-market or missing by jurisdiction, industry and company size.
• Drafting: precedent-based drafting in Word, plus clause rewrites with Quick Actions or a prompt.
• Price: $160 per user per month, or $1,740 per user per year, with 25 free queries per user and no credit card. The monthly plan is billed month to month, with no long-term contract, and 10 or more seats qualify for team pricing.
• Security: SOC 2 Type II, Zero Data Retention agreements with Gavel's AI model providers (OpenAI among them), and no training on customer data, prompts or documents.

Limits: Gavel Exec is built for transactional work. It has no case-law research database and isn't designed for litigation or e-discovery, redlining a specific document and building playbooks need the Word add-in, and iManage and NetDocuments integrations aren't available yet.

For deal lawyers, see Gavel Exec for transactional attorneys.

2. Spellbook: best for a full contract suite in Word

Best for: transactional lawyers, at firms or in-house, who want review, drafting and multi-document work inside one Word add-in.

Spellbook, which calls itself "The complete contract AI suite," says 5,000+ legal teams trust it. Its Word redlines arrive "with every suggestion tracked," Playbooks turn a team's standards into a checklist applied on each review, and Compare measures a contract against industry standards. Associate handles multi-document work.

• Price: not published; it depends on how many team members are on the license. About $350 per user per month is reported by Gavel customers.
• Trial: 7 days free, with extended trials possible for larger organizations.
• Security: SOC 2 Type II. Under its Zero Data Retention agreements, model providers don't train on or store your data.

Limits: a quote requires a demo, and the Playbook Build Service appears only in Spellbook's in-house package. See Spellbook vs Gavel Exec.

3. Claude for Word: best for teams already paying for Claude

Best for: lawyers on a paid Claude plan who want AI edits in Word's review pane.

Claude for Word is Anthropic's add-in for Word on Windows, Mac and the web. Anthropic says it can "Edit with tracked changes, respond to comment threads," and in tracked changes mode each edit is a revision you accept or reject. Its open-source Claude for Legal plugins include a reviewer for vendor master services agreements (MSAs) that "Reviews a vendor MSA against your playbook and produces a redline memo."

• Price: included in paid Claude plans. Pro is $20 per month ($17 billed annually), and a Team standard seat is $25 per month ($20 billed annually) for teams of 2 to 150. Anthropic lists no free trial for either.
• Data: no model training on Team and Enterprise content by default; Anthropic's pricing page lists training on Pro content as opt-out. Claude for Word deletes inputs and outputs within 30 days and doesn't inherit custom retention settings.
• Status: generally available on all paid plans, per the product page; the help article still says beta.

Limits: the legal plugins are reference templates your team adapts and maintains, and Anthropic says they "do not represent Anthropic's legal positions." Its Claude for Word page mentions no market benchmarking. See Claude for Word vs Gavel Exec and Claude for Word for lawyers.

4. Microsoft Copilot for Legal: best for organizations already on Microsoft 365 Copilot

Best for: legal teams in organizations that already license Microsoft 365 Copilot.

Copilot for Legal adds more than 20 legal skills to Copilot in Word desktop and Cowork, and LawNext reported it generally available on October 15, 2026. You upload a playbook as a .docx file, Copilot splits it into editable topics with rules and example clauses, and the review returns "negotiation-ready redlines with tracked changes." It also drafts from templates or earlier contracts.

• Price: included with Microsoft 365 Copilot commercial subscriptions. Microsoft 365 Copilot runs $30.00 a user each month on yearly billing ($31.50 monthly with an annual commitment), and Microsoft 365 Copilot Business starts at $21.00 a user each month on yearly billing ($18.00 in the first year under a promotion that ends December 31, 2026). Both sit on top of a qualifying Microsoft 365 plan.
• Trial: one month free for Microsoft 365 Copilot Business, credit card required. Confirm with Microsoft that your plan includes the legal skills.
• Research and jurisdiction: Microsoft says outputs "may not incorporate live legal databases" and that Copilot "is not jurisdiction-aware by default," and it tested the skills mainly in United States English.

Limits: Microsoft's documentation names only Word desktop and Cowork, so confirm support for Word on the web, and LawNext listed research plugins from partners including Bloomberg Law and Trellis while noting that Westlaw, CoCounsel and LexisNexis were missing. See Microsoft Copilot vs Gavel Exec.

5. Astra for Law: best for large firms in the United States that want OpenAI's legal model

Best for: law firms in the United States in OpenAI's Trusted Access program that want legal research and custom tools on OpenAI models.

OpenAI describes Astra for Law as GPT-6 Astra optimized for legal work, pairing a dedicated legal search index with custom instructions for analysis and drafting, and LawNext reported its release on September 17, 2026. The index covers United States case law, statutes, regulations, court rules and administrative decisions, and LawNext put the corpus at more than 230 million URLs.

• Access: offered first to some law firms in the United States through Trusted Access and Codex, for eligible attorneys and the people they supervise, with API support planned. Firms request early access through their OpenAI account team or OpenAI sales. LawNext reported the program targets Am Law 200 firms.
• Price: not published.
• Plugins: LawNext counted 26 partner plugins at launch, including Thomson Reuters, Harvey, Legora and iManage.
• Word: the Astra for Law help article doesn't mention Word; ChatGPT for Word is a separate add-in.

Limits: access is limited to selected firms, the research index covers United States law, and OpenAI's help article doesn't mention in-house teams. See Astra for Law vs Gavel Exec.

6. CoCounsel: best for Westlaw subscribers who also review contracts

Best for: firms that already use Thomson Reuters products and want research and contract review from one vendor.

CoCounsel, Thomson Reuters' legal AI, answers from Westlaw and Practical Law as well as your firm's documents. In CoCounsel for Microsoft Word, Compare to playbooks checks a contract against a custom or pre-built Practical Law playbook, labels each clause missing, having issues or acceptable, and ranks issues as high risk, major or minor. You insert or accept each suggested revision from the add-in and use Word's Track Changes to accept or reject changes, and Thomson Reuters also offers a new transactional drafting agent to compare and review contracts.

• Price: Thomson Reuters' solo and small firm plan for CoCounsel Legal starts at $551.85 a month.
• Trial: free trial on request.
• Volume: bulk review handles as many as 10,000 documents and 100 questions, and CoCounsel connects to iManage and NetDocuments.
• Security: Thomson Reuters says customer data is never used to train its underlying models.

Limits: the solo and small firm price bundles research and drafting with contract review, so a firm that only needs contract markup pays for research it may not use. See CoCounsel vs Gavel Exec.

7. GC AI: best for in-house lawyers who want one assistant for contracts and everyday questions

Best for: in-house lawyers who use ChatGPT for both contract work and day-to-day legal questions and want a tool built for that role.

GC AI says it's "built exclusively for in-house legal teams." It works in a web app and a Word add-in that drafts, reviews and redlines, runs automated first-pass reviews against your team's standards, and connects to Gmail, Slack, Drive, HubSpot and other apps. Research covers more than 14 million United States court opinions.

• Price: the Individual plan, for solo or fractional general counsel, is $500 a month. Team plans are quoted on request, billed yearly, and include one legal database of your choice.
• Trial: 14 days without a credit card, including the Word add-in and team review playbooks.
• Security: SOC 2 Type II, plus agreements with OpenAI and Anthropic for zero data retention.

Limits: GC AI is built only for in-house teams, United States case law is an add-on on the Individual plan, and GC AI's site shows no market benchmarking. See GC AI vs Gavel Exec.

How to choose a ChatGPT alternative

1. Sort your ChatGPT use. Drafts, summaries and clause explanations may be fine on ChatGPT Business. Reviewing the other side's paper against your positions calls for playbooks and tracked-change redlines.
2. Check what you already license. Microsoft 365 Copilot customers can try Copilot for Legal, Claude subscribers can try Claude for Word, and Westlaw subscribers can ask Thomson Reuters about CoCounsel.
3. Gather your prompts into one playbook document. Collect the liability caps, indemnity positions and governing-law preferences you keep in ChatGPT prompts, custom instructions or project files. Gavel Exec can generate playbook rules from that document.
4. Test two or three tools on the same contract this week. Gavel Exec's 25 free queries and GC AI's 14 days need no credit card, and Spellbook offers 7 days. Take a deal you've closed and compare each tool's redline with the version you actually sent.
5. Ask about data and jurisdiction. Find out whether each vendor trains on your documents, how long it keeps them and which jurisdictions it covers. Copilot for Legal was tested mainly in United States English and Astra for Law indexes United States law, while Gavel Exec benchmarks by jurisdiction and offers European Union, Canada and Australia hosting.

Switching from ChatGPT: what to bring with you

• Your saved contract-review prompts, custom instructions and project instructions. Put them in a checklist and Gavel Exec can turn it into playbook rules.
• A few signed agreements for each contract type you see most, to check new redlines against terms you've accepted.
• Your templates or clause library, for drafting from precedent.
• A note of which ChatGPT plan held client documents, so you can compare its data terms with the new vendor's.

More comparisons: all Gavel comparisons, Spellbook alternatives, CoCounsel alternatives, Harvey alternatives, our roundup of the best AI contract review tools for lawyers and how attorneys use ChatGPT and Claude.