How to compare two Word documents

Updated 30 September 2026

You have two versions of a document and need to know exactly what changed. Reading them side by side misses things: a number in a table, a sentence that moved, a word that became bold. Here are three reliable ways to find every difference, and when each one makes sense.

1. Word's built-in Compare

If you have Microsoft Word on a computer, it can compare two files for you:

1. Open Word and go to the Review tab.
2. Select Compare, then Compare... (compare two versions of a document).
3. Choose the Original document and the Revised document.
4. Select More to choose what to compare, such as formatting, tables, headers and footers, and moves.
5. Select OK. Word opens a new compared document with the differences as tracked changes.

Good for: quick checks when you already have Word and want a tracked-changes result. Watch out for: the result can be noisy when formatting changed a lot, and there's no summary report to file with a review.

2. Online diff websites

Many free websites compare documents if you upload both files. They are fast and work on any device.

Good for: non-confidential documents. Watch out for: most upload your files to their servers, which many companies don't allow for contracts, SOPs, specifications or anything under NDA. Many also flatten documents to plain text, so formatting and table structure are lost.

3. A private comparer that runs in your browser

RevisionProof reads both .docx files inside your browser and compares them there, so nothing is uploaded. It shows word-level edits, moved paragraphs, table cell changes, formatting, headers, footers, footnotes and comments, with a change list that tells you which section each change is in.

Good for: confidential documents and reviews that need a record, because it can produce a redline .docx and a change report with file hashes. Watch out for: it compares .docx only; save older .doc files as .docx first.

Tips for any method

• Accept or reject tracked changes first in both versions if you want to compare final text. Otherwise you may be comparing markup rather than content.
• Always compare the approved original against the revision, not against an intermediate draft.
• Check tables and headers separately; they're where small, important changes hide.
• Keep the comparison output with the review record if the document is controlled.