How to Compare Two Word Documents for Differences

Word has a built-in comparison feature made for exactly this - lawyers call the output a "blackline." It's powerful but only available in desktop Word, and it's more setup than you need for a quick check of what changed in the wording.

Quick answer

In desktop Word, use Review > Compare > Compare, pick your two documents, and Word generates a marked-up copy showing every change as tracked edits. Word Online doesn't have this feature. For a faster check without Word at all, copy the text from both documents and paste it into a browser-based text diff tool.

Built-in Compare in Word

Open desktop Word, go to the Review tab, click Compare, then Compare... again from the dropdown. Choose your original document and your revised document, then click OK. Word produces a new document with every change shown as a tracked edit - insertions underlined, deletions struck through - plus a summary pane listing each change.

Before running the comparison, the dialog lets you choose which types of changes to include: formatting, comments, moved text, and more. Turn off formatting comparison if you only care about wording changes and not font or spacing differences between the two files.

Word Online limitation (no Compare)

The Compare feature does not exist in Word Online, the browser version of Word accessed through Microsoft 365. If you're working from a browser without desktop Word installed, you'll need either a machine with the desktop app or a different approach entirely.

Quick alternative: paste both versions into a free browser diff

Select all the text in each document (Ctrl+A, Ctrl+C), then paste one into each panel of a text diff tool. This strips formatting and compares purely the wording - which is usually all you need when you just want to know "what changed" without generating a formal blackline document. It also works from any device with a browser, including one without Word installed at all.

Tracked changes vs diff - when each wins

Tracked changes are recorded as edits happen, while someone is actively working on a document with Track Changes switched on - every keystroke is logged in real time. A diff comparison, on the other hand, takes two finished documents that were never linked by tracked changes and works out the differences afterward.

Use tracked changes when you control the editing session from the start. Use a comparison - Word's Compare feature or a plain text diff - when you're handed two separate final files and need to find out what's different between them after the fact.

Paste both documents' text and see the difference instantly.

Open Text Diff →

Want more on comparing text online?

See the full guide to comparing text online, including download options.

Read the guide →

Frequently Asked Questions

How do I compare two Word documents without Word?

Copy the text from each document and paste it into the Text Diff tool. It shows exactly which lines were added, removed, or changed - no Word license or install needed.

Where is Compare in Word?

In desktop Word, go to the Review tab, click Compare, then Compare, and choose your original and revised documents. Word generates a new document showing every difference as tracked changes.

Can I compare two documents in Word Online?

No - the Compare feature is only available in the desktop version of Word. Word Online (the browser version) doesn't include it. If you only have browser access, paste the text of both documents into a browser-based diff tool instead.

Does Word Compare ignore formatting differences?

By default, Word's Compare can flag formatting changes (font, bold, spacing) alongside text changes, which is useful for legal blacklining but adds noise if you only care about wording. You can adjust which comparison settings are included from the Compare Documents dialog before running it.

What is the difference between tracked changes and a document comparison?

Tracked changes are recorded live as someone edits a document with Track Changes turned on - every edit is logged as it happens. A comparison instead takes two already-finished documents that were never linked by tracked changes and works out the differences after the fact. Use tracked changes when you control the editing process; use Compare when you're handed two separate final versions.

Can I compare a Word document against plain text?

Yes - copy the text out of the Word document (Ctrl+A, Ctrl+C) and paste it into a text diff tool alongside your plain text version. Formatting is dropped once you copy plain text, so the comparison is purely about wording, which is often exactly what you want for a quick check.