The fastest way to spot differences between Word documents

Microsoft Word has a built-in comparison tool that shows you exactly what changed between two versions of the same document. Open the document you want to compare, go to the Review tab, click Compare, and select Compare again from the dropdown. Choose the older version of the document, and Word will create a new document showing every insertion, deletion, and formatting change marked in color.

The comparison appears in a three-pane layout: the original document on the left, the revised document in the middle, and a summary of changes on the right. Insertions show in blue, deletions in red, and moved text in green. You can accept or reject each change individually, or accept all changes at once. This method works whether you're comparing two files on your computer or documents stored in OneDrive or SharePoint.

Key Takeaways

  • Word's Compare tool creates a marked-up version showing every change in color, making differences visible at a glance.
  • You can review changes one at a time and accept or reject them individually before saving the final version.
  • If you need to see documents side by side without marking changes, use View > View Side by Side instead of Compare.
  • Google Docs shows a version history automatically, so you don't need a separate comparison step for documents stored there.
  • For plain-text or PDF files, dedicated comparison tools like DiffPDF or Notepad++ may show differences more clearly than Word.

Using Word's Compare tool step by step

Start with the newer version of the document already open in Word. Click the Review tab at the top of the screen. In the ribbon, find the Compare button — it's usually in the upper left area of the Compare group. Click the dropdown arrow next to it and select Compare (not Combine, which merges changes from multiple reviewers).

A dialog box opens asking you to choose the original document. Navigate to the older version and click Open. Word then generates a new document showing all differences. The left pane displays the original, the center pane shows the revised version with markup, and the right pane lists every change. Scroll through the center pane to see each change highlighted. Use the Accept and Reject buttons in the Review tab to decide on each change, or click Accept All Changes to approve everything at once.

When to use View Side by Side instead

If you want to read both documents without Word marking up changes, use View > View Side by Side instead of Compare. This places the two documents next to each other on your screen so you can scroll through both at the same time and spot differences yourself. This approach works better when you're checking content rather than tracking edits — for example, if you're comparing a draft you wrote to a client's version and want to see the full context of each change.

Side-by-side view does not create a new document or mark changes. Both original files remain unchanged. You can close one document and keep working in the other without any markup getting in your way. This is useful when the documents are similar enough that you can spot differences visually, or when you want to understand the reasoning behind changes before deciding whether to keep them.

Comparing documents stored in OneDrive or SharePoint

If both versions are stored in OneDrive or SharePoint, you can use Word's Compare tool the same way — just open the newer version from the cloud and select the older version when prompted. Word handles the file paths automatically. You can also check the version history directly in OneDrive or SharePoint without opening Word at all. Right-click the file in OneDrive, select Version history, and you'll see a timeline of every saved version with the date and time each was saved.

Clicking on an older version in the timeline opens it in a read-only preview. You can then open it in Word and use Compare to see what changed since then. This approach is helpful if you're not sure which version you need to compare against, because you can browse the timeline and pick the right starting point before opening Word.

Using Google Docs for automatic version tracking

If your documents are in Google Docs instead of Word, you don't need a separate comparison step. Google Docs keeps a complete version history automatically. Click File > Version history > See version history to open a timeline on the right side of the screen. Each version shows the date, time, and name of the person who made changes. Click any version to see what it looked like at that point.

To compare two specific versions, open the older version from the timeline, then open the newer version in another browser tab. You can then read both side by side. Google Docs also shows who made each change and when, which is useful if multiple people are editing the same document. Unlike Word's Compare tool, Google Docs does not create a marked-up version — you're viewing the actual saved states of the document at different points in time.

Comparing PDFs and other file types

Word's Compare tool only works with .docx files. If you need to compare PDFs, use a dedicated PDF comparison tool like DiffPDF (free, open-source) or Adobe Acrobat's comparison feature (paid). For plain-text files, Notepad++ (free, Windows) or Sublime Text (paid, cross-platform) show differences side by side with color highlighting. These tools are often faster than Word for spotting changes in text-heavy documents because they focus only on the content without formatting markup.

If you have a PDF and a Word document you need to compare, convert the PDF to Word first using a tool like Adobe Acrobat or an online converter, then use Word's Compare tool. Keep in mind that conversion is not always perfect — complex layouts, images, and special formatting may not transfer cleanly. For straightforward text documents, the conversion usually works well enough for comparison purposes.

Handling tracked changes vs. comparison

Tracked changes and comparison are different tools. Tracked changes (Review > Track Changes) records edits as you make them, showing who changed what and when. Comparison looks at two finished documents and figures out what's different between them, even if neither one has tracked changes turned on. Use tracked changes when you're actively editing and want a record of every keystroke. Use comparison when you have two versions and need to see the net result of all changes at once.

If a document already has tracked changes in it, you can still use Compare to see how it differs from another version. Word will show both the tracked changes from the original document and any new differences it finds when comparing to the second document. This can make the markup complex, so it's usually clearer to accept or reject all tracked changes first, then run Compare on the final versions.

Frequently Asked Questions

Can I compare more than two documents at once?

Word's Compare tool works with two documents at a time. If you need to compare three or more versions, compare the first two, then compare the result to the third. Alternatively, use the version history in OneDrive or Google Docs to browse multiple versions and spot patterns in how the document changed over time.

What if Word says the documents are too different to compare?

This usually means the documents have very different structures or one is corrupted. Try opening both documents and manually reviewing them side by side using View > View Side by Side. If one document is corrupted, try opening it in a different process or recovering an earlier version from your file history.

Does comparison work if the documents have different formatting?

Yes. Word's Compare tool looks at content first and flags formatting changes separately. If one document uses Arial and the other uses Times New Roman, Word will mark that as a change. You can see formatting differences in the markup and decide whether to keep them or revert to the original formatting.

Can I undo a comparison after I've accepted changes?

Yes, use Ctrl+Z (or Cmd+Z on Mac) to undo the acceptance of changes, or close the comparison document without saving it. If you've already saved the document, you can open the original version and run Compare again to start over.

Is there a way to compare documents without creating a new file?

View > View Side by Side shows both documents without creating a new file. Both originals stay unchanged. If you want to keep a record of the comparison, you'll need to save the marked-up version that Compare creates, or take screenshots of the side-by-side view.