The fastest way to compare two Word documents

Word has a built-in comparison tool that shows you exactly what changed between two versions of a document. Open the document you want to use as your starting point, go to the Review tab, click Compare, and select Compare again from the dropdown menu. Then choose the other document you want to compare it against. Word will create a new document showing all the differences — additions in blue, deletions in red, and moved text marked separately.

This method works best when you have two complete versions of the same document and want to see what was added, removed, or changed. The comparison happens instantly, and you can accept or reject each change one at a time if you want to build a final version from the results.

Key Takeaways

  • Word's Compare tool is on the Review tab and creates a new document showing all changes between two files in different colors.
  • Additions appear in blue, deletions in red, and moved text gets its own marking so you can spot every difference at a glance.
  • You can accept or reject individual changes in the comparison document to create a final version that combines the parts you want.
  • If you need to see changes made over time by different people, use Track Changes instead of Compare — it works differently and suits collaborative editing better.

Step-by-step: Running a comparison

Start with the document you consider the original or base version. Open it in Word. Click the Review tab at the top of the screen.

In the Review ribbon, find the Compare button. It usually sits in the middle-right area of the ribbon. Click it, then click Compare from the dropdown menu that appears (not "Combine" — that's different and merges tracked changes instead).

A dialog box opens asking you to pick the document to compare against. Navigate to the file you want to compare with your current document and click Open. Word processes both files and opens a new document showing the comparison results. The original document stays open on the left side of your screen, the revised document on the right, and the comparison results appear in the center.

Reading the comparison results

The comparison document uses color coding to show what changed. Blue text means something was added in the revised version. Red text with strikethrough means something was deleted. Text that moved from one place to another gets marked as moved, usually with a note in the margin.

On the left side of the document, you'll see a vertical line marking where changes occurred. Click any change to jump to it. The left panel shows a summary of all changes — you can expand or collapse sections to focus on specific parts of the document.

If the comparison looks wrong or missed changes, the most common cause is that one document uses different formatting or line breaks than the other. Word compares the actual text content, so invisible formatting differences don't show up as changes.

Accepting or rejecting changes from the comparison

Once you see the comparison results, you can build a final version by accepting the changes you want and rejecting the ones you don't. Right-click any change in the comparison document and select Accept Change or Reject Change. Alternatively, use the Review tab again — the Accept and Reject buttons let you move through changes one at a time.

When you accept a change, Word removes the color coding and keeps the new text. When you reject a change, it removes the new text and restores the original. Once you've decided on all the changes, save the comparison document as your final version. The original files stay unchanged.

If you have many changes and want to accept most of them with only a few exceptions, use Accept All from the Review tab, then go back and reject only the ones you don't want. This is faster than clicking through dozens of individual changes.

When to use Compare instead of Track Changes

Compare and Track Changes are different tools for different situations. Use Compare when you have two finished versions of a document and need to see what's different between them. This works well when someone sent you a revised copy and you want to understand what they changed, or when you're merging feedback from multiple people who each edited their own copy.

Use Track Changes when you're working on a document together in real time or want to record who made each change and when. Track Changes marks edits as you make them, so you build a history of the document as it evolves. Compare is a one-time snapshot showing the final difference between two versions.

If you're collaborating with others, Track Changes is usually the better choice because it shows who changed what and when, and people can see your edits as you make them. Compare is better for reviewing work after the fact or comparing versions that were edited separately without tracking.

Troubleshooting common comparison problems

If the comparison shows changes that don't look right, check whether both documents use the same font, spacing, or margins. Word compares text content, but formatting differences can sometimes make the comparison confusing. If one document has extra line breaks or different paragraph spacing, Word might mark text as moved when it's actually just reformatted.

If the Compare button is grayed out, you probably don't have a document open. Open the document you want to use as the base first, then run the comparison. If you're comparing documents with very different structures — like one that's been heavily reorganized — the comparison might show more changes than you expected because Word is matching text by position as well as content.

If you need to compare more than two documents, run the comparison twice. Compare document A and B first, then compare the results with document C. This takes longer but shows you all three versions' differences.

Frequently Asked Questions

Can I compare documents that are different file types, like Word and Google Docs?

Word's Compare tool only works with Word documents (.docx, .doc). If you need to compare a Word file with a Google Docs file, download the Google Doc as a Word file first, then run the comparison. The download process sometimes changes formatting, so check the downloaded version before comparing.

Does Compare show me who made each change?

No. Compare shows what changed, but not who changed it or when. If you need to know who made specific edits, use Track Changes instead, which records the author's name and timestamp for each change.

What happens to the original documents after I run Compare?

The original documents stay exactly as they are. Compare creates a new document with the comparison results. You can close the comparison document without saving it, and your original files won't change.

Can I undo a comparison?

The comparison itself can't be undone because it creates a new document. But you can close the comparison document without saving it. If you already saved the comparison results and want to go back, use Ctrl+Z to undo recent changes, or close the file without saving and reopen your original.

Why does Compare show changes in places where I didn't edit anything?

This usually happens when one document was edited in a different version of Word or on a different operating system. Invisible formatting changes — like different line-break rules or spacing — can cause Word to mark text as changed even though the visible content looks the same. Check the formatting of both documents and make sure they match before comparing.