How to Use the Microsoft Word Compare Feature to Find Document Differences

If you email a contract or a report to a colleague for review, they are supposed to turn on “Track Changes” before making edits. Unfortunately, people frequently forget. When they email the document back to you, you are left staring at two seemingly identical files, completely unsure of what sentences they changed, deleted, or added.

Instead of reading both documents side-by-side line by line, you can use the built-in Compare feature in Microsoft Word. This tool acts like a digital proofreader, instantly scanning the original file and the edited file, and generating a brand new document that automatically highlights every single difference using standard redline formatting.

How to Compare Two Documents

To use this feature, you must have both the original document and the edited document saved somewhere on your computer.

1. Open Microsoft Word. You do not need to open either of the specific files; a blank document is fine.
2. Click the Review tab in the top ribbon menu.
3. Look to the far right of the ribbon and click the Compare button.
4. From the small dropdown menu that appears, select Compare… again.

A “Compare Documents” dialogue box will appear, featuring two main panels: “Original document” on the left and “Revised document” on the right.

5. In the Original document panel, click the folder icon and locate your original, unedited file.
6. In the Revised document panel, click the folder icon and locate the file your colleague sent back to you.
7. Look for the small More >> button at the bottom of the dialogue box. Click it to reveal advanced settings.
8. Under “Show changes at”, ensure Word level is selected (this provides the most readable results).
9. Under “Show changes in”, ensure New document is selected. This ensures your original files are not accidentally overwritten or altered.
10. Click OK.

How to Read the Comparison Results

Microsoft Word will process the files and open a new document containing four distinct panels.

• The Center Panel (Compared Document): This is the most important panel. It displays the final, merged text. Any text your colleague deleted will be crossed out with a red line. Any text they added will be underlined and written in red font.
• The Left Panel (Revisions Pane): This acts as a summary. It lists exactly how many insertions, deletions, and formatting changes were made, providing a quick overview of how heavily the document was edited.
• The Right Panels (Original & Revised): These two stacked panels show the two source documents side-by-side for context.

How to Accept or Reject Changes

You can now treat this comparison document exactly like a file that used traditional Track Changes.

1. Place your cursor at the very beginning of the centre document.
2. On the Review tab in the ribbon, look for the “Changes” group.
3. Click the Next button. Word will instantly highlight the first difference it found.
4. Click Accept to keep your colleague’s edit, or click Reject to revert that specific sentence back to how it was written in your original file.
5. Continue clicking Next and evaluating each change until you reach the end of the document.

Once you are satisfied, simply save this new document as the final, official version.