How to Compare Two Documents

Comparing two documents means finding exactly what changed between them — added lines, removed words, or altered formatting — so you can review edits, merge versions, or catch errors. This guide covers built-in tools in Microsoft Word and Google Docs, plus free online diff tools for PDFs and text files. You’ll need both documents saved on your computer or in your cloud drive, and access to the software you plan to use.

What You’ll Need

• Two versions of the document (e.g., draft and final, or original and edited copy).
• Microsoft Word (2013 or later) or a Google account for Google Docs.
• For PDF or plain text files, an internet connection to use a free online diff tool.

Step-by-Step

Method 1: Microsoft Word (Windows or Mac)

1. Open the first document in Word. This is the version you’ll compare against.
2. Go to the Review tab in the ribbon.
3. Click Compare (or Compare… in older versions). In the dropdown, select Compare….
4. In the dialog box, under Original document, click the folder icon and select the first file. Under Revised document, select the second file. If you’re not sure which is which, the original is usually the earlier version.
5. Click OK. Word will analyze both files and open a new window showing the differences.
6. Review the results: the left pane lists all changes (insertions, deletions, formatting changes). The main pane shows the revised document with tracked changes. The right pane shows both documents side-by-side.
7. Use the Accept or Reject buttons in the Review tab to finalize which changes to keep, or just read through the changes and close without saving to keep the original files untouched.

Method 2: Google Docs

1. Upload both documents to Google Drive (if they aren’t already there).
2. Open the first document in Google Docs.
3. Click Tools in the menu, then select Compare documents.
4. Click Choose document and select the second file from your Drive.
5. Optionally, check the box to Include differences in comments — this adds a comment for each change, which can be easier to review.
6. Click Compare. Google Docs will create a new document titled “Comparison of [original name] and [revised name]”.
7. In the new document, changes appear as suggested edits (insertions and deletions). Use the comment suggestions to accept or reject each one.

Method 3: PDF or Text Files (Online Diff Tools)

1. Open a free online diff tool in your browser (search for “online diff tool” or “PDF compare”).
2. Upload both files. Most tools accept PDF, Word, or plain text files.
3. Click Compare or Find Differences.
4. Review the side-by-side or inline output. Added text is usually highlighted in one color (e.g., green), removed text in another (e.g., red).
5. Download the comparison report if you need to keep a record.

Common Mistakes

• Choosing the wrong file as “original” — if you swap them, Word/Google Docs will show your edits as reversals, which is confusing.
• Comparing files of different formats — e.g., trying to compare a .docx with a .pdf. Word can’t do this directly; convert one file first.
• Forgetting to save changes before comparing — if the revised document is still open with unsaved edits, the compare tool may use the saved version instead.
• Ignoring formatting changes — Word’s compare includes formatting by default, but if you only care about text, you can turn off formatting comparison in the Compare settings.
• Using online tools for confidential documents — uploading sensitive files to a third-party site can be a privacy risk. Use offline tools for anything confidential.

Tips

• Before comparing, make a backup copy of both files so you can always revert.
• In Word, you can click Show Source Documents in the Compare pane to hide or show the original and revised versions, helping you focus on the changes.
• For long documents, use the Reviewing Pane in Word (under Review > Reviewing Pane) to see a list of all changes with context.
• If you only need to check for accidental changes (like a missing comma), use the “Compare” feature instead of manually scrolling through both files.
• In Google Docs, the comparison result is a new file, so you can share it with collaborators without altering the originals.

Troubleshooting

Word says “Cannot compare” or “The documents are not compatible.” This usually happens when one file is an older format (.doc) and the other is newer (.docx). Convert the older file to the newer format (File > Save As > Word Document) and try again.

Google Docs doesn’t show the “Compare documents” option. This feature is only available in the desktop version of Google Docs, not the mobile app. Open Google Docs in a web browser on your computer.

The online diff tool shows garbled text or missing characters. This often occurs with PDFs that contain scanned images rather than selectable text. Use an OCR tool first to convert the scanned PDF to text, then compare.

Changes are not showing up even though you know the files differ. Check that both files are the correct versions — it’s easy to accidentally upload the same file twice. Also, make sure you’re looking at the correct pane (in Word, the main pane shows the revised document with changes).

Frequently Asked Questions

Can I compare two documents in Word without opening both?

Yes. Open one document, then use Review > Compare and select the second file. Word will open the comparison in a new window.

Does Google Docs compare formatting changes?

Yes, Google Docs’ compare feature includes formatting changes (like bold or font size) as suggestions, but it’s less detailed than Word’s formatting comparison.

Can I compare PDF files for free?

Yes, many free online tools exist, but they may have file size limits or watermark the output. For sensitive PDFs, consider using Adobe Acrobat’s trial or a desktop tool.

How do I compare two documents in Word on a Mac?

The steps are the same: go to the Review tab, click Compare, and select both files. The interface is nearly identical to Windows.

What if I only want to see text changes, not formatting?

In Word, in the Compare dialog, click Settings and uncheck Formatting. In Google Docs, you can filter the suggestions to only show insertions/deletions.

Can I compare more than two documents at once?

No, both Word and Google Docs only compare two at a time. To compare three versions, compare the first two, then compare the result with the third.

Related

• RCS Chats On or Off in Google Messages
• How to Choose a Phone That Supports VoLTE on Your Carrier
• Data Center AI Readiness: Step-by-Step Evaluation