The fastest way to compare two Word documents
Microsoft Word has a built-in comparison tool that shows you exactly what changed between two versions of a document. Open the newer version, go to the Review tab, click Compare, and select the older version from your files. Word will create a new document that marks every addition, deletion, and formatting change in a different color, with a panel on the left showing all the changes listed by location.
If you don't have Word installed, Google Docs also compares documents, though the process is different. Upload both versions to Google Drive, open the newer one, click the three-dot menu, select Version history, then click on an earlier version to see what changed. You can also use free online tools like Diff Checker or Microsoft's free Word Online version if you're working in a browser.
The choice between these methods depends on what you're comparing and whether you need to keep the comparison for later. Word's comparison creates a permanent record you can save. Google Docs shows changes but doesn't save a separate comparison document. Online tools work without logging in but may not preserve formatting as accurately.
Key Takeaways
- Word's Compare feature (Review tab) creates a new document showing all changes in color, with a summary panel listing every edit by location.
- Google Docs version history shows what changed between saves, but you cannot save the comparison as a separate document.
- Free online comparison tools like Diff Checker work without software installation but may lose formatting details in complex documents.
- Word's comparison works best for tracking edits across multiple versions; Google Docs works best for real-time collaboration where you want to see who changed what.
Using Word's built-in Compare tool
Open the newer version of your document in Word. Click the Review tab at the top of the screen. In the Compare group, click Compare, then select Compare Documents from the dropdown. A dialog box will open asking you to choose the original document. Navigate to the older version and click Open.
Word creates a new document that displays both versions side by side. The left panel shows the original document, the right panel shows the revised document, and the center shows a merged version with all changes marked. Additions appear in blue, deletions in red, and formatting changes in a different color. The left sidebar lists every change with its location in the document — click any change to jump to it.
You can accept or reject individual changes by right-clicking them or using the buttons in the Review tab. If you want to keep the comparison for your records, save this new document with a name like "Document_Comparison_Date". The original files remain unchanged.
Comparing documents in Google Docs
Upload both versions to Google Drive if they aren't there already. Open the newer version in Google Docs. Click the three-dot menu in the top right corner and select Version history. A panel opens on the right showing every save with a timestamp. Click on any earlier version to see what that version looked like.
The current version appears on the left, the selected earlier version on the right. Changes are highlighted in color — additions in blue, deletions in red. However, Google Docs does not create a separate comparison document you can save. The version history is tied to that specific file, so if you need to share the comparison with someone else or keep it separate, you'll need to take screenshots or export both versions and use a different tool.
This method works well if you're tracking changes within a single document over time, especially in collaborative work where you want to see which version was saved when. It's less useful if you need to compare two completely separate files or create a formal record of differences.
Using free online comparison tools
Websites like Diff Checker, Copyleaks, and Scribd's document comparison tool let you upload two Word documents and see the differences without installing software. Go to the tool's website, click the upload button, select your two documents, and click Compare. The tool displays the documents side by side with changes highlighted.
These tools work in any web browser and don't require you to log in or create an account. They're useful if you're on a computer without Word installed or if you want to compare documents quickly without saving anything. However, they may not preserve complex formatting, track changes, or handle very large files as well as Word does. Some free tools also have file size limits — typically 25 to 100 MB per document.
Read the tool's privacy policy before uploading sensitive documents. Most free tools delete files after a few hours, but some may store them longer. If you're comparing confidential information, Word's Compare tool or Google Docs is safer because the files stay on your own computer or your Google Drive account.
Comparing documents in Word Online
If you have a Microsoft account but Word isn't installed on your computer, you can use Word Online through a web browser. Go to Office.com, sign in, and click Upload to add both documents to your OneDrive. Open the newer version, click Review, then Compare, and select the older version. The comparison works the same way as the desktop version — Word creates a new document showing all changes in color.
Word Online's Compare tool is less full-featured than the desktop version. Some formatting options and advanced features may not appear, and very large documents can be slow. However, it's free if you have a Microsoft account, and you don't need to install anything. The comparison document saves automatically to your OneDrive, so you can access it from any device.
When to use each comparison method
Use Word's Compare tool if you have Word installed, need to track detailed changes, or want to accept or reject edits one at a time. It's the most powerful option and handles complex formatting well. Use Google Docs version history if you're already working in Google Docs or collaborating with others in real time — it shows you who made each change and when. Use free online tools if you don't have Word or Google Drive, need to compare documents quickly, or want to avoid uploading to any account. Use Word Online if you have a Microsoft account but no desktop software, or if you need the comparison saved to OneDrive for access across devices.
If you're comparing documents with tracked changes already turned on, Word's Compare tool will show those tracked changes plus any new differences between the versions. This can make the comparison harder to read, so consider accepting or rejecting all tracked changes in the original document first, then running the comparison.
Frequently Asked Questions
Can I compare two Word documents on my phone or tablet?
Word Online works on mobile browsers, so you can use it to compare documents if you have a Microsoft account and OneDrive. However, the mobile interface is smaller and harder to navigate. Free online comparison tools also work on phones, but viewing two documents side by side on a small screen is difficult. For serious comparison work, a computer or tablet with a larger screen is more practical.
What if one document is in .docx format and the other is in .doc format?
Word's Compare tool handles both formats without any problem. It will convert older .doc files automatically and show all changes. If you're using an online tool, check whether it supports both formats — most do, but some may require you to convert to .docx first.
Does Word's Compare tool show formatting changes like font size or color?
Yes. Word marks formatting changes separately from text changes. In the left sidebar, you'll see entries for both content changes and formatting changes. You can filter the view to show only certain types of changes if the document has many edits.
Can I undo a comparison if I accidentally accept all changes?
Yes. The comparison creates a new document, so your original files are never changed. If you accept changes in the comparison document and save it, you can still go back to the original versions. If you haven't saved the comparison yet, you can close it without saving and start over.
What's the difference between Compare and Track Changes?
Track Changes records edits as someone makes them in real time, showing who changed what and when. Compare looks at two finished documents and shows what's different between them, regardless of who made the changes or when. Use Track Changes during collaborative writing; use Compare to review two separate versions after the fact.