Compare Two Open Documents in Word: A Step-by-Step Guide

To compare two open documents in Microsoft Word, save both files, then choose Review > Compare > Compare on Windows. Select the earlier file as the original and the later file as the revised document, then choose OK. Word creates a comparison copy marked with the differences, leaving your two source documents intact. This is useful for checking edits when you do not have Track Changes records.

What You’ll Need

The desktop version of Word, such as Word for Microsoft 365 on Windows or Mac. Word for the web does not provide the same full Compare Documents workflow; open the files in the desktop app to compare them.
Both documents available in Word. Save the latest edits first so the comparison uses the versions you intend to check.
A little time to choose which file is the original and which is the revised version. Word uses that direction to label additions and deletions.

Step-by-Step

Open both files in Word. Open the two documents you want to check in the desktop app. They can be open in separate windows or tabs. If they are not open yet, open them from File > Open. The files should be Word documents or another format Word can open and compare.
Save the current versions. Use File > Save in each document, or press Ctrl+S on Windows. This avoids comparing a saved copy that does not include your latest edits. If you are unsure which file should be the baseline, check the file names, dates, or document contents before proceeding.
Open the comparison command. Select the Review tab on the ribbon, then choose Compare and Compare again from its menu. In some ribbon layouts, Compare may be displayed directly as a button in the Compare group. On Word for Mac, use Review > Compare > Compare Documents; the wording and layout can vary slightly between releases.
Choose the original document. In the Compare Documents dialog, open the Original document list and select the earlier or baseline file. If it is not listed, use the folder or browse control beside the field and locate it. The original is the version Word treats as the starting point, not necessarily the file that happens to be open in the foreground.
Choose the revised document. In the Revised document list, select the later version or browse to it. Check both names carefully before continuing. Word compares the revised document against the original: content found only in the revised file is generally shown as an insertion, and content removed from the original is shown as a deletion.
Set comparison options if needed. Select More in the dialog to see additional settings. You can choose which kinds of differences Word should examine, such as text changes, formatting, comments, headers and footers, footnotes, or tables. For a general edit check, leave the relevant text options enabled. If you only want to review wording, consider turning off formatting comparison so font or spacing changes do not clutter the result.
Choose where Word puts the results. In the dialog, look for the option for showing changes in. Select New document for a separate comparison copy. This is usually the safest choice: it keeps both source files as they are and lets you review the marked-up result independently. The other choices display the comparison in one of the source documents, so use them only if that is what you intend.
Run and inspect the comparison. Select OK. Word opens a comparison document with changes displayed as revision markup, often alongside a Reviewing pane or lists of the source and revised documents. Review the marked text and use the Review tab’s controls to navigate between changes. If the markup is difficult to read, adjust the display using the tracking and markup controls rather than assuming a difference is missing.
Save the result as a separate file. Choose File > Save As and give the comparison a distinct name, such as Project-Comparison-Review.docx. Save it in a location where you can find it, and avoid overwriting either source file. You can then share the marked comparison or continue reviewing it in Word.

Word’s comparison is a new review document, not a side-by-side image of two pages. It identifies differences in a combined document using revision-style markup. The original and revised files remain useful references, especially if you need to confirm why a particular change was flagged.

Common Mistakes

Reversing the original and revised files. Word still finds differences, but additions and deletions may appear in the opposite direction from what you expect. If the result looks backward, rerun Compare with the files in the other fields.
Choosing two copies of the same file. Similar names make it easy to select the wrong version. Check the document title, folder, or contents in the selection dialog before confirming.
Comparing before saving. If one document has unsaved changes, the file on disk may not represent what you meant to compare. Save each document first, then run the comparison.
Expecting two panes with synchronized scrolling. Compare creates a marked-up comparison document. It is different from opening two windows and choosing a side-by-side viewing command, which helps you look at pages but does not automatically mark edits.
Including every formatting difference unintentionally. Small changes to fonts, spacing, or layout can make the markup look busy. Use the dialog’s More options to narrow what Word checks when you mainly care about text.
Editing the source while reviewing the result. Keep the comparison output and the source files distinct. Save the result under a new name so you do not accidentally replace a clean original or revised copy.

Tips

Use clear version names. Names such as Draft-Original and Draft-Edited are easier to distinguish than several files called Final. A date or version number can help, too.
Review markup in manageable passes. First scan the document for major additions and deletions, then check formatting or comments if those matter. The Review tab can help you move through changes one at a time.
Keep the two source files. The comparison is useful for review, but retaining both inputs lets you verify context or rerun the comparison with different options.
Use Compare for independent versions. If you have not tracked changes while editing, Compare can identify differences between the two saved versions. If changes are already tracked in one file, review that file’s existing markup as well; a comparison may surface differences beyond the tracked edits.
Protect sensitive material. Before sharing the comparison copy, inspect it for comments, document properties, or other information you do not want to distribute. The comparison may include content from both versions.

Troubleshooting

The Compare command is unavailable or missing. Confirm that you are using the desktop Word app and have a document open. On the ribbon, check the Review tab and its Compare group; if the ribbon is simplified, expand it or look for the Compare menu. In Word for the web, choose the option to open the document in the desktop app, then use the Review tab there.

One or both documents do not appear in the lists. Use the browse control in the Compare Documents dialog to locate each file on your computer or accessible storage. If the file is stored online, make sure it is available to Word and that you have permission to open it. You can also close and reopen the document, then retry the comparison.

The result is empty or seems to miss edits. Verify that you selected two different versions and saved the intended changes. Check the comparison options, because a disabled category—such as formatting—will not be represented in the result. Also make sure the changed text is not in a part of the document you excluded from comparison, such as a header or footnote.

The result contains too much markup. Formatting changes, layout shifts, or widespread document restructuring can create many flags. Rerun the comparison with only the categories you need, or use the markup display controls to focus on insertions and deletions. For a clean wording review, compare text changes without formatting where that option is available.

Word reports that a file cannot be compared. Check that the file opens normally, is not password-protected in a way that blocks access, and is saved in a supported format. If necessary, open it in Word and save a working copy as a Word document, then compare that copy. Keep the original file unchanged if it is important.

Frequently Asked Questions

Does comparing documents change either original file?
When you choose New document for the comparison output, Word creates a separate result and leaves the source files unchanged. Save the result under a new name to preserve that separation.

Can I compare two documents that are already open?
Yes. Open the Compare Documents dialog and select the documents in the Original document and Revised document fields. If an open file is not listed, browse to its saved location instead.

Can Word compare documents side by side?
The Compare feature produces a marked-up comparison document rather than simply placing two pages beside each other. You can open both files and use Word’s window viewing tools for visual inspection, but that does not automatically identify edits.

Can I compare Word documents in a browser?
For the full Compare Documents workflow described here, use desktop Word. Word for the web can handle many review tasks, but it does not offer the same desktop comparison command; open the files in the desktop app to create a comparison.

How do I accept or reject the differences?
In the comparison document, use the controls on the Review tab to accept or reject individual changes, or move through them one at a time. Be careful to save your reviewed copy separately if you need to retain the original comparison markup.

Can Word compare only selected parts of two files?
The Compare dialog’s options let you control categories of content, but it is not a general tool for selecting arbitrary passages in each file. For a partial review, compare the documents and focus on the relevant section, or make separate working copies containing the passages you need to examine.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

More in How-to basics

Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

Spotted an error in this guide? Let us know.