How to compare two versions of a contract
DraftStack, Inc. · Published October 16, 2026
Every deal lawyer has the same fear: the other side sends back a “clean” draft with changes nobody told you about. This guide covers how to compare two versions of a contract so that nothing slips through, whether you use Word, a comparison tool, or a shared workspace.
Why a tracked-changes file is not enough
Tracked changes show what the other side chose to track. They do not show edits made with tracking switched off, text pasted in from another document, or changes accepted in an earlier round. The only reliable method is to compare the new draft against the last draft you actually sent or agreed, not against the file the other side marked up.
A method that works
- Keep one source of truth. Decide which version is the current draft. Name it by round, such as “Draft 4”, not “final” or “final2”.
- Compare against that version, every time. When a markup arrives, run a comparison between it and the draft you circulated. In Word this is Review, Compare, Compare two versions.
- Read the comparison, not the cover email. Check every insertion, deletion and moved block. Pay attention to defined terms, cross-references and numbers, which often change without a note.
- Check the formatting-only noise. Re-numbered clauses and re-flowed tables produce long comparison reports. Filter them out in your comparison settings so the real changes stand out.
- Log each change as an open point. Write down what changed, who proposed it, and whose move it is. A change you have not logged is a change you will forget.
- Accept or reject in one controlled pass. One person produces the next draft. Two people editing the same file is how changes go missing.
Common ways a comparison goes wrong
- Comparing the markup to an older draft than the one you sent.
- Comparing a PDF of one version to a Word file of another, which creates thousands of false differences.
- Missing changes inside tables, footnotes, headers and exhibits.
- Trusting a document that was saved by someone else after you checked it.
Checking a markup against what you actually sent
The weak point in the method above is the starting file. If you cannot show that the draft you are comparing against is the one you circulated, a comparison tells you less than it appears to. DraftStack records the version that was circulated on a deal and checks any markup you drop in against it, so you know whether the other side started from the right draft. The check runs in your browser, and only fingerprints of the file are sent, not its contents.
You can try it on your first deal, which is free. The other side is invited by link and does not need an account or pay anything.