How to Redline Contracts with AI: A Lawyer's Guide

A note from the author, CEO and Founder of Gavel: Before I became a tech founder, I was a practicing lawyer, one who spent more hours than I care to admit redlining contracts deep into the night, fueled mostly by caffeine and a healthy dose of stubbornness. If you're reading this, you're probably familiar with the pain: chasing down inconsistent definitions, fixing typos, and wondering how the clause you deleted twice somehow reappeared. This article is for you.

Artificial intelligence (AI) redlining is the use of AI software to review a contract and propose edits as tracked changes, the same markup a colleague would send you. To redline a contract with AI, open it in a tool that works inside Microsoft Word, tell the AI which party you represent and what the parties already agreed, run the redline, and review every suggested change before anything goes to the other side.

Key takeaways

• Redlines improve when you give the AI the party you represent, the term sheet or letter of intent, and your playbook or precedent.
• Tools that work inside Word apply suggestions as ordinary tracked changes, so the counterparty receives a normal markup.
• Clear prompts name the task, the context and the output you want back.
• Playbooks turn your negotiating positions into rules the AI checks on every agreement, which keeps a team's redlines consistent.
• You remain responsible for every change that goes out. The American Bar Association (ABA) expects lawyers to review AI output for accuracy.

Last updated October 29, 2026. Gavel makes Gavel Exec, which this guide uses for its examples.

What is AI redlining?

AI redlining is software that reads a contract, compares its terms with a standard and proposes specific edits, usually as tracked changes and comments. The standard can be your playbook, your precedent, a term sheet or general market terms.

A good AI redlining tool can:

• flag terms that are unfavorable to the side you represent
• propose replacement language for each issue it flags
• find provisions that are missing
• check a draft against a term sheet, letter of intent or prior draft
• explain the reason for each change, so you can decide whether to keep it

Redlining is the markup step. Contract review is the broader read that finds and explains issues, and many reviews end with a redline. Gavel's contract redlining feature covers the markup itself.

How do you redline a contract with AI?

Redlining a contract with AI takes six steps: open the contract in a Word-based tool, add the deal context, set your side and scope, run the redline, review each change, and refine before you send.

1. Open the contract where you edit it. Use a tool that runs inside Microsoft Word, so suggestions land in the document you already work in. Gavel Exec runs as a Word add-in for Windows, Mac (2016 or later), Word on the web and Microsoft 365, and as a web app. Tools that only work on a separate website add a step: you download their markup and reconcile it with your working draft.
2. Add the deal context. Attach the documents the redline has to respect, such as the signed letter of intent (LOI), the term sheet, the last turn of the draft or your own template. If you represent a tenant and attach the LOI, the AI can check rent, term, deposit and renewal rights against what the parties already agreed. In Gavel Exec, a Project holds the instructions and reference files for a matter, so every chat and redline on that deal starts from the same context.
3. Choose your side, your style and the scope. Tell the AI which party you represent and how hard to push. In Gavel Exec's Redline Document dialog, you set the negotiation style on a slider from light through market to aggressive, enter the party you represent, pick the jurisdiction and add any extra files or instructions. Redline the whole agreement, or select one clause, such as the indemnity, and limit the redline to it.
4. Run the redline. The AI reads the agreement and returns suggested changes. Look for a tool that ranks and explains them. Gavel Exec shows each suggestion with a priority level, such as High or Medium Priority, and the reasoning behind it, so you can work through the critical changes first.
5. Review each change and apply the ones you agree with. Read every suggestion against the deal and your client's goals, and edit or skip the ones that miss. In Gavel Exec, Apply All inserts the suggestions as tracked changes, and you accept or reject each one in Word as you would a colleague's markup.
6. Refine, explain and send. Complex agreements take more than one pass. Select a clause and ask for a rewrite, add negotiation comments that explain your changes to the other side, or run your playbook as a final check. The counterparty receives an ordinary Word document with tracked changes and comments.

How do you get better AI redlines?

Give the AI the instructions you would give a junior associate: the task, the context and what you want back. Seven habits make the biggest difference.

• Start with a summary. Before you redline a long agreement, ask for a summary or a list of the key risk areas. It shows you where to spend your attention.
• Write specific prompts. “Revise this indemnification clause to make it mutual, cap liability at the fees paid in the prior 12 months and exclude indirect damages” gets a better result than “improve this clause.”
• Load your precedent early. Upload your template, your positions checklist or a previously negotiated version at the start. The earlier the AI sees your standard, the less you correct later.
• Match the negotiation style to the deal. A light markup suits a counterparty you need to close with quickly. An aggressive markup shows you every available ask, and you choose which ones to make.
• Check definitions and cross-references. Ask the AI to list unused defined terms, undefined terms and broken section references. It takes seconds and catches errors that cause disputes later.
• Calibrate playbooks on your best template. Run a new playbook on an agreement you consider ideal and adjust the rules until it raises no flags. After that, each flag on a new draft points to a real deviation.
• Use a Project for a deal and chat for quick edits. A Project keeps instructions and reference files for a whole transaction. Chat handles one-off questions, such as rephrasing a sentence or explaining a clause.

Gavel Exec's suggestions adapt to each user's redlining style over time. For product-specific tips, see best practices for redlining in Gavel Exec.

What prompts work for AI redlining?

Strong prompts name the task, the context and the output. These ten cover most transactional redlining work.

What does an AI redline look like on a real deal?

Here is how a tenant-side lawyer might handle a 40-page office lease from the landlord's counsel with Gavel Exec in Word. The scenario is illustrative, and the figures are examples.

1. Compare the lease with the LOI. She attaches the signed LOI and asks for every term that doesn't match. The AI reports that rent is $5,500 a month against $5,000 in the LOI, the deposit is $15,000 against two months' rent, the term is five years against three, and the renewal option is missing.
2. Apply the fixes. She edits one suggestion, applies the rest as tracked changes and adds the renewal option the LOI promised.
3. Run a tenant-side lease playbook. The playbook flags a blanket consent requirement for assignment, an indemnity that makes the tenant cover the landlord's own negligence, and uncapped increases in operating expenses. She lowers the proposed cap because she knows this landlord's usual position.
4. Work clause by clause. She selects the default provisions and asks for a plain-English summary and any unusual risks. She asks whether the insurance requirements are typical, and the AI points out that the waiver of subrogation runs only one way.
5. Ask what's left. A final prompt asks what a tenant-side lawyer would usually push back on that the markup doesn't address. The AI flags a personal guaranty from the founder.
6. Send it. The landlord's counsel receives tracked changes plus short comments explaining the major points.

How should you review AI redlines before you send them?

Review AI suggestions the way you would review a junior associate's draft: against the deal, your client's goals and the law, before anything leaves your desk.

• Verify every substantive change. Read each edited clause in full and confirm it reflects the deal.
• Check anything the AI didn't get from you. Statutes, defined terms and facts the AI introduces need a source you can confirm.
• Make the strategic calls yourself. Drop points your client doesn't care about and add the ones the AI missed.
• Fix the tone. Edit comments to opposing counsel so they read the way you write.
• Keep client data in approved tools. Use software your firm or company has vetted for confidential documents.
• Be able to explain each change. If a client or partner asks why a clause changed, answer from your own analysis.
• Re-prompt when the output misses. Narrow the request, add context or ask for a shorter answer, and run it again.

The ABA's Formal Opinion 512 (July 29, 2024) applies the duties of competence, confidentiality and client communication to lawyers' use of generative AI and expects lawyers to review AI output for accuracy.

Which contracts are best suited to AI redlining?

AI redlining works best on agreements with recognizable structures and established market positions:

• nondisclosure agreements (NDAs), master services agreements (MSAs) and vendor agreements
• software as a service (SaaS) agreements and data processing agreements (DPAs)
• commercial leases and real estate purchase agreements
• stock and asset purchase agreements and other deal documents
• employment and consulting agreements

It helps less with highly bespoke agreements that have no comparable precedent, questions that turn on regulatory interpretation and multi-party deals with unusual structures. In those cases, use the AI for summaries, definition checks and drafting help, and keep the substantive markup in your own hands. For practice-specific guidance, see Gavel Exec for commercial contracts, corporate law and real estate law.

How does AI redlining compare with manual redlining?

Both aim for an accurate, balanced contract. AI-assisted redlining gets the first pass done faster and applies your standards the same way every time, while the lawyer keeps the judgment calls.

Martin Algie of MIA Contract Lawyers cut his first-cut reviews from 15 hours to about 5 with Gavel Exec. Read Martin's story.

What should you look for in an AI redlining tool?

Choose a tool that works where you draft, writes real tracked changes, explains its suggestions and protects client data. Check for:

• a Word add-in that writes standard tracked changes and comments
• settings for the party you represent, the negotiation style and the jurisdiction
• a priority and a reason for each suggested change
• playbooks you can build from your own checklists, spreadsheets or signed agreements
• market benchmarking, if counterparties argue about what is market
• security credentials: SOC 2 (System and Organization Controls 2) Type II, zero data retention with AI model providers, and no training on your documents
• a published price and a free trial

For a side-by-side comparison of ten tools, see the best AI contract review tools for lawyers. Gavel Exec costs $160 per user per month, or $1,740 per user per year, with 25 free queries per user and no credit card.

Is AI redlining secure and ethical?

AI redlining can meet a lawyer's obligations when the tool protects confidential information and the lawyer supervises the output. Formal Opinion 512 ties confidentiality to Model Rule 1.6, so ask each vendor where your documents go and whether they are used for training. Gavel Exec is SOC 2 Type II certified. Gavel has Zero Data Retention agreements with the AI model providers it uses, including OpenAI, and does not use customer data, prompts or documents to train AI models. Details are on the Gavel security page.

Frequently asked questions

Is AI redlining accurate?

AI redlining produces a useful first pass when you give it context: your side, the deal documents and your playbook. It is not accurate enough to send without review, so a lawyer should check every change before it goes out.

Can AI redline a contract in Microsoft Word?

Yes. Word add-ins such as Gavel Exec insert their suggestions as standard tracked changes and comments, which you accept or reject like any other markup.

Will the other side see that I used AI?

The counterparty receives an ordinary Word document with tracked changes and comments. Whether you tell your own client about AI use is a separate question, which ABA Formal Opinion 512 addresses.

Can AI replace a lawyer in contract negotiation?

No. AI handles the first pass and applies playbooks the same way every time. Deciding what to concede, what to hold and how to explain it to the client stays with the lawyer.

How much does AI redlining software cost?

Prices vary, and several vendors quote only through a demo. Gavel Exec costs $160 per user per month, or $1,740 per user per year, and each user starts with 25 free queries with no credit card.

Related reading: AI for transactional attorneys, AI terminology for lawyers and all Gavel Exec features. Try Gavel Exec free with 25 queries and no credit card, or request a demo.