To run a redline comparison in Word, click the Review tab, click Compare > Compare (called Compare two versions of a document), choose the Original document and the Revised document, and click OK. Word creates a new document that shows every difference as tracked changes: added text is underlined, deleted text is struck through, and changed lines are marked in the margin.
This works in Word for Microsoft 365, 2021, 2019, 2016, and 2013. Below you’ll learn how to fine-tune the comparison, read the results, and save or share the redline.
How to compare two documents
- Open Word (you don’t need to open either document first).
- Click Review > Compare > Compare.
- Under Original document, click the folder icon or the dropdown and choose the earlier version.
- Under Revised document, choose the newer version.
- Optionally, type a name in Label changes with so the changes are attributed to a person or version.
- Click OK.
Choose what to compare
Click More in the Compare Documents box to choose which differences to show, such as Formatting, Comments, Tables, Headers and footers, and Case changes. Under Show changes at, choose Word level (recommended) or Character level. Under Show changes in, choose New document to keep both originals untouched.
How to read the redline
- The compared document in the center shows all changes as tracked changes.
- The Revisions pane on the left lists each change. Click one to jump to it.
- The original and revised documents may appear on the right for reference. Turn them off with Compare > Show Source Documents > Hide Source Documents.
Use Review > Next and Previous to step through changes, and Accept or Reject to finalize them.
How to save or share the redline
- Save the compared document with a name like “Contract v1 vs v2 redline.”
- To send it as a PDF with changes visible, set the markup view to All Markup, then choose File > Save As > PDF. In Options, make sure Document showing markup is selected.
Compare vs. Combine
Compare shows the differences between two versions. Combine (under the same button) merges tracked changes from several reviewers into one document.
Troubleshooting
- Too many changes shown: Turn off Formatting in More options to focus on text edits.
- Compare is grayed out: The current document may be protected or in Read Mode. Switch to Print Layout or close protected files.
- Documents have tracked changes already: Word treats existing changes as accepted when comparing. Accept or reject them first for the clearest result.
Frequently asked questions
What is a redline?
A redline (or blackline) is a document that shows the differences between two versions, often used for contracts and legal documents.
Can I compare PDFs in Word?
Word can open PDFs and convert them, then compare, but layout changes may show as differences. A dedicated PDF comparison tool may work better.
Does Word for the web have Compare?
Word for the web has limited compare features. Use the desktop app for full redlines.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
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