Best AI Contract Redlining Software for Lawyers

The best artificial intelligence (AI) contract redlining software marks up a full agreement in Microsoft Word as tracked changes, explains each edit and applies your own negotiating positions. For lawyers who redline in Word and want a published price, our pick is Gavel Exec at $160 per user per month. Spellbook, LegalOn and Microsoft Copilot for Legal are the main alternatives.

Key takeaways

• All ten tools on this list redline inside Microsoft Word or connect to it, and all ten can apply a playbook, the written record of the positions your side accepts.
• Four show a price on their own sites: Gavel Exec ($160 per user per month), goHeather (from $200 per month billed annually), BlackBoiler (Starter at $1,250 per user per year) and Microsoft, whose Copilot for Legal comes with a Microsoft 365 Copilot license ($30 per user per month paid yearly, on top of a qualifying Microsoft 365 plan).
• Ask every vendor whether its edits arrive as native Word tracked changes with your name on them. Several vendors do not say so on their own sites.
• Microsoft announced general availability of Copilot for Legal on October 15, 2026, with a worldwide rollout through mid-December. If you already pay for Microsoft 365 Copilot, test it first.
• Contract lifecycle management (CLM) platforms such as Ironclad and Juro also redline. Ironclad activates its Word agent through Ironclad account teams, and Juro runs AI review from its own contract platform or from Word.

Last updated October 29, 2026. We checked every product detail on the vendor's own website on October 28-29, 2026. Gavel makes Gavel Exec.

What is AI contract redlining software?

AI contract redlining software reads an agreement, compares each clause with the positions you set for the party you represent, and proposes edits as tracked changes in Word. Good tools also explain why each edit was made, so the reviewing lawyer can accept, change or reject it quickly.

The inputs are the same ones a lawyer uses: which side you represent, a playbook of standard and fallback positions, approved precedent, and sometimes a term sheet or letter of intent. The output is a marked-up draft with comments the other side can read. For a step-by-step method, see how to redline a contract with AI. For how Gavel Exec handles it, see contract redlining software.

How do the best AI contract redlining tools compare?

Gavel Exec, LegalOn, BlackBoiler, goHeather and Microsoft Copilot for Legal state on their own sites that their edits arrive as Word tracked changes. Gavel Exec and goHeather are the only add-ins here with a published price and a free trial that needs no credit card. The table compares all ten.

Which AI redlining tool fits which team?

Each tool below lists where it runs, how its redlines arrive, what it costs and who it suits. Every fact links to the vendor page we checked.

1. Gavel Exec: best for lawyers who redline in Word and want 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. We picked it because it combines three things: edits that land as Word tracked changes, a reason attached to every edit, and a price you can see before a demo. More than 2,000 legal organizations in 28 countries use Gavel, which Relativity acquired in June 2026.

• Where it runs: Word add-in for Word for Windows, Word for Mac 2016 and later, Word on the web and Microsoft 365, plus a web app at exec.gavel.io.
• How redlines arrive: Gavel Exec redlines a full agreement for the party you represent, using your positions, your playbooks and a negotiation style (light, market or aggressive). Each edit goes in as a Word tracked change with a priority level and the reasoning behind it. You can edit a change before applying it, filter by priority and add comments, and the other side sees ordinary tracked changes.
• Playbooks: Built-in playbooks written by practicing attorneys, rules you write by hand, or rules generated from your checklists, spreadsheet playbooks and signed agreements.
• Security: System and Organization Controls (SOC) 2 Type II, zero data retention with its AI model providers and no training on customer data (Gavel security).
• Price: $160 per user per month, or $1,740 per user per year, with 25 free queries per user and no credit card. Paid plans include 1,000 queries per user per month, and teams of 10 or more seats get discounted pricing.
• Best for: Law firms and in-house teams that negotiate in Word and want to test on their own agreements first.
• Source: contract redlining software; Gavel Exec pricing

2. Spellbook: best for transactional teams that also want post-signature contract management

• Where it runs: Word add-in. Google Docs appears in Spellbook's integrations list.
• How redlines arrive: Spellbook says you can "negotiate from your side, with every suggestion tracked" and that its playbooks add redlines "directly to your contract, in your name". Its learning center describes showing suggestions as strikethroughs or as comments only. Whether every suggestion arrives as a native Word tracked change is not stated on Spellbook's own pages.
• Recent changes: Autonomous Contract Management, a contract management product with a repository, became generally available on October 7, 2026. Comprehensive Reviews, which runs a playbook, risk check and proofread in one step, is in early access.
• Price: Not published. Spellbook prices by team size and offers a 7-day free trial.
• Best for: Transactional lawyers in firms and in-house teams. Spellbook says it is "trusted by 5,000+ legal teams".
• Source: Spellbook; Spellbook pricing; Autonomous Contract Management announcement; Spellbook September 2026 update. Compare: Spellbook vs. Gavel Exec.

3. LegalOn: best for in-house departments that want pre-built playbooks

• Where it runs: Word add-in, Word for the web and LegalOn's web platform.
• How redlines arrive: LegalOn's AI Revise creates redlines in one click and works with Word's own Track Changes, according to a LegalOn post last updated July 23, 2024. Since September 4, 2026, AI Revise also drafts missing provisions in the Word add-in and Word for the web, and in Word for the web you can set an editor name, such as "Legal", as the author of comments and tracked changes. LegalOn gives guidance and sample clauses for every issue and shows its reasoning as it reviews. Whether each tracked change carries its own explanation is not stated.
• Playbooks: More than 135 attorney-built playbooks by contract type and negotiating position, plus your own positions written in plain English.
• Price: Not published. LegalOn sells three plans (Core Review, Contracting Suite and Productivity Suite), and Core Review includes unlimited AI contract review and redlining. No trial is mentioned on the pricing page.
• Best for: In-house teams, from a solo attorney or a fractional general counsel (GC) to large departments.
• Source: AI Revise in Microsoft Word; New at LegalOn; LegalOn pricing; LegalOn contract playbooks. Compare: LegalOn vs. Gavel Exec.

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

• Where it runs: Word for desktop, where the legal plugin is on by default, and Cowork, where users add the legal plugin, according to Microsoft's message center notice.
• How redlines arrive: Microsoft says the legal skills produce "negotiation-ready redlines with tracked changes", work in documents that already contain tracked changes and review contracts against a playbook. Microsoft tested them primarily in United States English. Microsoft's Copilot for Legal documentation says it provides citations that link to the source language. It does not say whether every proposed edit carries its own reason.
• Availability: Microsoft announced general availability on October 15, 2026, with a worldwide rollout through mid-December 2026, for users with Microsoft 365 Copilot commercial licenses. The earlier Legal Agent is being retired.
• Price: No separate price for the legal skills. The Microsoft 365 Copilot add-on costs $30.00 per user per month paid yearly and requires a qualifying Microsoft 365 plan. Whether the lower-priced Copilot Business add-on qualifies is not stated; see the licensing note below.
• Best for: Firms and legal departments that already license Microsoft 365 Copilot and want to test AI redlining before buying a separate tool.
• Source: Microsoft message center MC1509799; Microsoft transparency documentation; Microsoft 365 Copilot pricing. Compare: Microsoft Copilot vs. Gavel Exec.

5. CoCounsel for Microsoft Word: best for teams already on Thomson Reuters

• Where it runs: Word add-in, plus the CoCounsel web app, Outlook and Teams.
• How redlines arrive: Compare to playbooks groups issues as high risk, major or minor, with Redlines and Guidance tabs. You insert a suggested revision at the cursor or accept it, and Thomson Reuters tells users to accept or reject changes with Word's Track Changes. Whether every suggestion lands as a tracked change is not stated.
• Playbooks: Your own playbooks or Practical Law pre-built playbooks.
• Price: Thomson Reuters offers online pricing for firms of up to 10 attorneys (the figure is not shown on the page) and sales quotes for larger firms. Its site lists free trials and demos; ask whether a trial includes CoCounsel for Microsoft Word.
• Best for: Law firms and corporate legal departments that already use Practical Law or Westlaw.
• Source: CoCounsel contract review help; CoCounsel Legal plans and pricing. Compare: CoCounsel vs. Gavel Exec.

6. Harvey for Word: best for large firms buying a full legal AI platform

• Where it runs: Word add-in, plus Harvey's web app, Outlook add-in and mobile app.
• How redlines arrive: Each playbook rule returns Acceptable, Needs review or Not acceptable with an explanation. You apply suggested edits as redlines with an editable justification comment, and you can export results to an .xlsx file. The tracked-change format is not stated on the help page we checked.
• Price: Not published; Harvey sells through demos.
• Best for: Large law firms and corporate legal teams. Harvey says more than 80 Am Law 100 firms use it.
• Source: Harvey Word add-in playbooks guide; Harvey for Word; Harvey. Compare: Harvey vs. Gavel Exec.

7. Ironclad Contract Review Agent for Microsoft Word: best for teams already on Ironclad

• Where it runs: Microsoft Word, connected to an Ironclad account. The tool was formerly called Ironclad Jurist.
• How redlines arrive: Ironclad describes "playbook-driven redlining directly into Word", with suggested edits that "include supporting rationale". Its screenshots show tracked changes and comments. Customers activate it through their Ironclad account team; whether teams without Ironclad can buy it is not stated.
• Price: Not published; Ironclad sells through demos.
• Best for: In-house teams that already run contracts through Ironclad's CLM platform.
• Source: Ironclad Contract Review Agent. Compare: Ironclad vs. Gavel Exec.

8. Juro: best for in-house teams that run simple contracts through one platform

• Where it runs: Juro's browser-based contract platform; Juro says its AI can review and redline contracts in Word, and it connects to Slack and Teams.
• How redlines arrive: Juro's AI agent reviews third-party contracts against your playbooks and marks them up, and each redline names the playbook rule it applied. You accept, edit or skip each one. Whether the redlines arrive as Word tracked changes or in Juro's own editor is not stated. Juro reviews English contracts only.
• Price: Not published. Plans are custom, based on contract volume and integrations, with unlimited users.
• Best for: In-house legal and business teams that handle simple, repeatable contracts.
• Source: Juro AI contract review; Juro pricing.

9. BlackBoiler: best for high-volume review of the same agreement types

• Where it runs: Microsoft Word.
• How redlines arrive: BlackBoiler turns "your playbook and approved language into first pass tracked changes in Microsoft Word", building its rules from your prior redlines, approved language and guidance, and it adds comments. Veris, a chat tool for playbooks, also runs in Word.
• Price: Starter, Pro and Enterprise plans. Starter costs $1,250 per user per year and Pro $3,000 per user per year, and Enterprise is quoted during scoping. Annual billing saves 17%, and the 7-day trial requires a credit card.
• Best for: In-house teams, law firms and contract managers who review the same agreement types over and over.
• Source: BlackBoiler; BlackBoiler pricing. Compare: BlackBoiler vs. Gavel Exec.

10. goHeather: best for small businesses and small firms that want a monthly price

• Where it runs: Word add-in and a web app that reviews Portable Document Format (PDF) files.
• How redlines arrive: goHeather says it redlines "with tracked changes and a short note beside each edit", and it gives "red light, green light" insights based on your playbooks.
• Price: Starter costs $400 per month, or $200 per month billed annually, for one seat. Team pricing is by request. The 7-day free trial needs no credit card.
• Best for: Small and midsize businesses and small law firms.
• Source: goHeather; goHeather pricing. Compare: goHeather vs. Gavel Exec.

Also considered

Claude for Word from Anthropic places edits as tracked revisions in its suggested-edits mode; Anthropic's help center calls it a beta for paid plans while claude.com calls it generally available, so check the current status (Claude for Word vs. Gavel Exec). DocJuris produces playbook-driven redlines in Word for mid-market and enterprise in-house teams on an annual platform fee. Legora's Word add-in drafts, redlines and reviews (Legora vs. Gavel Exec). LawY generates tracked changes in Word with an explanation for each change. Luminance offers contract redlines and playbook-driven suggestions in its own platform, and its Word integration covers negotiation checklists and review (Luminance vs. Gavel Exec). GC AI and Ivo also redline in Word and are covered in our roundup of best contract playbook software.

Which AI redlining tools work inside Microsoft Word?

All ten work in Microsoft Word. Gavel Exec, Spellbook, BlackBoiler and goHeather make Word the main workspace; LegalOn, CoCounsel and Harvey pair Word with their own web apps; Ironclad and Juro connect Word to their contract platforms; and Copilot for Legal is built into Word for desktop.

Before rollout, confirm the add-in works on the Word versions your lawyers use. Gavel Exec lists Word for Windows, Word for Mac 2016 and later, and Word on the web.

Do the redlines arrive as real tracked changes the other side can accept?

For Gavel Exec, LegalOn, BlackBoiler, goHeather and Microsoft Copilot for Legal, the vendor says so on its own site. For Spellbook, CoCounsel, Harvey, Ironclad and Juro, the vendor pages we checked describe redlines without confirming every detail, so test the output yourself.

Three things matter once a redlined draft leaves your desk:

1. Native Track Changes. The other side should be able to accept or reject each edit in Word without your tool installed. Open a test redline on a computer that does not have the add-in.
2. Author name. Edits should show your name or your team's name. LegalOn lets you set an editor name such as "Legal" in Word for the web, and Spellbook says redlines go in "in your name".
3. Comments the other side can read. Some tools write explanations for your own team and separate negotiation comments for the counterparty. Check which ones the tool inserts into the document before it goes out.

How do the top AI redlining tools compare on price?

Four of the ten publish a price. Gavel Exec costs $160 per user per month, goHeather costs $400 per month or $200 per month billed annually for one seat, and Copilot for Legal comes with a Microsoft 365 Copilot license at $30 per user per month paid yearly, on top of a Microsoft 365 plan. BlackBoiler publishes Starter ($1,250 per user per year) and Pro ($3,000 per user per year) prices and quotes Enterprise during scoping. CoCounsel offers online pricing for firms of up to 10 attorneys without showing the figure. Spellbook, LegalOn, Harvey, Ironclad and Juro quote prices through sales.

See Gavel Exec pricing for team rates at 10 or more seats.

Can Microsoft Copilot redline contracts now, and is it enough?

Yes, Copilot for Legal produces tracked-change redlines in Word and reviews contracts against a playbook. Whether it is enough depends on your licenses, your languages and how much control you need over positions and explanations.

Microsoft announced general availability on October 15, 2026, and the rollout runs through mid-December 2026. Before you rely on it, check four things:

1. Licensing. Microsoft lists Microsoft 365 Copilot commercial licenses as the requirement. Its pages do not say whether the lower-priced Business add-on qualifies.
2. Language. Microsoft says it tested the legal features primarily in United States English.
3. Playbooks. Microsoft says you can create a playbook from a set of precedents, but it has not published how playbooks are stored or shared. Ask how your team would maintain one.
4. Explanations. Microsoft says Copilot for Legal provides citations that link to the source language. Confirm whether each proposed edit also carries a reason.

For a feature-by-feature view, see Microsoft Copilot vs. Gavel Exec.

How is AI redlining different from document comparison and CLM?

Document comparison shows the differences between two versions you already have. AI redlining proposes new edits based on your positions. A CLM platform stores, routes and tracks contracts, and some CLM platforms now include AI redlining.

• Document comparison: Litera Compare, Draftable and Word's own Compare produce a blackline between two drafts. Draftable costs US$129 per user per year for enterprise and non-legal users and US$261 per user per year for law firms and legal teams, billed annually (Draftable pricing).
• AI redlining: Gavel Exec, Spellbook, LegalOn, BlackBoiler, goHeather and Copilot for Legal propose edits to a counterparty's draft.
• CLM with AI redlining: Ironclad and Juro manage the full contract lifecycle and add AI redlining in Word for teams on their platforms.

A team can use both: an AI redliner on incoming paper and a comparison tool to check what the other side changed in the next turn. Our guide to best AI contract review tools for lawyers covers the wider review category.

How should a firm test an AI redlining tool before buying?

Run every shortlisted tool on the same three to five agreements you negotiated recently, then compare the redlines with what your lawyers sent.

1. Pick test documents. Use a nondisclosure agreement (NDA), a master services agreement (MSA) and one agreement from your own practice, such as a lease or an employment agreement.
2. Load your positions. Write or import your playbook, including standard and fallback positions and the points where you walk away.
3. Redline for both sides. Run each tool once for your usual client and once for the counterparty, and see whether the edits change.
4. Check the output in Word. Confirm native tracked changes, the author name and which comments the other side will see.
5. Score the edits. Count edits your lawyers would keep, change or delete, and note any missed issue.
6. Review security and ethics. American Bar Association (ABA) Formal Opinion 512 (July 29, 2024) expects lawyers to understand their AI tools, protect client information under Model Rule 1.6 and review the output. Ask each vendor for its SOC 2 Type II report and its terms on data retention and model training.

Two related roundups cover the next questions buyers ask: best contract playbook software for checking agreements against your positions, and contract benchmarking tools for testing whether a clause is market.

How did we choose and check these tools?

We included tools that propose edits to a contract in or for Microsoft Word, apply a playbook and are sold to lawyers or legal teams today. We checked every product detail on the vendor's own website on October 28-29, 2026, and wrote "not stated" where we could not find a detail. Gavel makes Gavel Exec; we held it to the same standard and linked each claim to its source.

Frequently asked questions

What is the best AI contract redlining software?

For lawyers who redline in Microsoft Word and want a published price, our pick is Gavel Exec at $160 per user per month, with 25 free queries per user to start. In-house teams that want a broader contracting suite usually compare LegalOn and Spellbook, and organizations already licensed for Microsoft 365 Copilot can test Copilot for Legal first.

Can Microsoft Word redline a contract with AI?

Yes. Microsoft announced general availability of Copilot for Legal on October 15, 2026, for Microsoft 365 Copilot commercial license holders, and it produces tracked-change redlines in Word. Add-ins such as Gavel Exec, Spellbook, LegalOn and BlackBoiler also redline inside Word.

Do I need AI redlining software if I already use Track Changes?

Track Changes records the edits a person types. AI redlining software proposes the edits for you, based on your playbook and the party you represent, and inserts them as tracked changes that you accept or reject.

Can AI redlining tools work on the other side's paper?

Yes. Reviewing the other side's draft is the main job for most tools on this list. Open the draft in Word so the edits land as tracked changes, and convert a PDF from opposing counsel to a Word document first.

Is it safe to put client contracts into an AI redlining tool?

It can be, if the vendor meets your confidentiality obligations. Ask for a SOC 2 Type II report, zero data retention agreements with the AI model providers and a written commitment not to train on your documents, and have a lawyer read every redline before it goes out.

How much does AI contract redlining software cost?

Gavel Exec costs $160 per user per month or $1,740 per user per year, and goHeather's Starter plan costs $200 per month billed annually. Most other vendors quote prices through sales.

Related: best AI contract review tools for lawyers, best contract playbook software, contract benchmarking tools, how to redline a contract with AI and Gavel Exec alternatives and comparisons. Try Gavel Exec free with 25 queries and no credit card.