The counterparty sends back version 4 of the supply agreement. Their email says "a few minor edits". You want to know three things: what actually changed, which of those changes matter, and what to push back on.
In short: In Wysor you upload both Word versions of a contract into a chat and ask for a redline. You get a .docx with native Word tracked changes (every insertion and deletion, ready to accept or reject in Word), a list of what changed, and a summary of which changes matter legally or commercially and where to push back. The final legal assessment stays with you.
What you can do right now
- Open a chat in the Wysor web app.
- Upload the earlier version (for example
Supply_Agreement_v3.docx) and the later version (Supply_Agreement_v4.docx). - Ask: "Redline v3 against v4 and tell me which changes I should push back on."
Wysor compares the two files and returns:
- A redline document. A new file named after the later version, for example
Supply_Agreement_v4 (redline).docx. It contains native Word tracked changes, so you open it in Word and accept or reject each change as usual. The revision author shown in Word is your name. - A list of what changed. Every insertion and deletion, with the number of each.
- A summary of what matters. The AI goes through the changes and tells you which ones shift risk or money, for example a payment term moving from 30 to 60 days, a longer notice period, or a liability cap that has quietly become unlimited, and suggests where to push back.
If you leave the file names out, Wysor compares the two most recent Word uploads in the chat, with the older one treated as the original. If several files have similar names, it asks which two you mean instead of guessing.
What a redline is
A redline (or blackline) is a version of a document that shows every change between two drafts: deleted text struck through, inserted text underlined, usually in color. In contract negotiations it is the standard way to show the other side, or your own client, exactly what moved between rounds. Redline software and document comparison software produce this view automatically from two files, so nobody has to mark changes by hand.
How to compare two Word documents in Word itself
If you only need the marked-up view, Word has a built-in comparison:
- In Word, open the Review tab.
- Click Compare, then Compare... (Compare two versions of a document).
- Under Original document, choose the earlier version. Under Revised document, choose the later version.
- Click OK. Word opens a new document with the differences as tracked changes.
That gives you the redline. What it does not give you is a reading of it. Word shows that "100% of annual fees" was deleted and "unlimited" was inserted; it does not tell you that this removes your liability cap, that it matters more than the twelve formatting and wording edits around it, or how to respond.
What Wysor adds to the redline
The redline file is the same kind of output Word produces: native tracked changes you can review, accept and reject. The difference is what comes with it.
- Prioritisation. Long agreements often come back with dozens of changes. The summary separates the changes that carry legal or commercial weight (liability, payment, termination, notice, indemnities, governing law) from cosmetic edits.
- Pushback points. For the changes that matter, the AI suggests what to object to and why, so you can draft your reply or your counter-redline faster.
- Follow-up in the same chat. Ask follow-up questions on any clause, request replacement wording, or draft the cover email to the other side, with both versions and the change list still in context.
- Contract Review skill. If you work in an agent, you can activate the Contract Review skill, which reviews clauses for risk and suggests replacement language.
For deeper contract work, including research grounded in real case law, see legal AI in Wysor and our guide to analyzing contracts with AI.
What it does and what it does not do
What it does:
- Compares two Word documents (.docx) that you uploaded in the same chat.
- Produces a .docx redline with native Word tracked changes.
- Lists every insertion and deletion and summarises which changes matter legally or commercially.
- Checks both uploaded files and the generated redline with a malware scan before they are opened or offered.
What it does not do:
- Word .docx files are required. Old .doc files, password-protected files and rights-protected (IRM) files cannot be compared. Save them as a normal .docx first.
- No redline file for PDFs. If you upload two PDFs, the AI can read and compare the text and tell you what changed, but it does not produce a tracked-changes file.
- Formatting-only differences are not listed. The change list covers text that was inserted or deleted. If two versions differ only in formatting, Wysor reports that the text is the same.
- File size limit. Each file can be up to 25 MB. Very large or complex documents may take too long to compare; in that case, compare them in parts.
- Download on the web. In the mobile app you get the summary in the chat, but the redline file itself can be downloaded in the web app at wysor.io.
- Your own uploads. The comparison works on files you uploaded yourself in that chat.
- No legal advice. The summary helps you find and prioritise changes. Whether a change is acceptable, and what to agree, remains your professional judgment.
Confidentiality
Contract drafts are confidential by nature. Wysor is hosted in the EU, runs with zero data retention at the AI model providers, and customer data is not used for training. That makes it suitable for client documents where general consumer chatbots are not.
FAQ
Can AI redline a contract? Yes. Wysor compares two Word versions of a contract and produces a redline with native tracked changes, plus a summary of which changes matter and what to push back on. The decision on each change stays with you.
How do I compare two Word documents for free? Use Word's own feature: Review, Compare, Compare two versions, choose the original and the revised document, then OK. Word creates a new document with the differences as tracked changes.
Can I accept or reject the changes in Word? Yes. The redline uses native Word tracked changes, so you review it in Word like any other marked-up document.
Does it work with PDFs? The AI can compare the text of two PDFs and describe the differences, but a tracked-changes redline file needs two .docx files.
If you negotiate contracts regularly, try it on your next round of comments: upload both versions to a chat at wysor.io and ask for the redline.
