ALTABRIG Tools

Guides & Insights

How to compare two versions of a contract

A practical method for finding what changed between contract versions and reviewing changes in context.

When two versions of a contract look similar, important differences can be easy to miss. A useful review process separates finding changes from deciding what those changes mean.

Automated comparison helps with the first task. Human legal or commercial judgment is still needed for the second.

1. Keep a clear original and revised version

Before comparison:

  • identify the earlier version;
  • identify the revised version;
  • keep both source files unchanged;
  • use filenames that make the order obvious.

If you are unsure which file is authoritative, resolve that first. A technically perfect comparison of the wrong pair is still the wrong review.

2. Prefer the best available source format

DOCX contains structured text and document information. PDF is a rendered-page format. Comparison evidence can therefore differ.

If you have both editable source and PDF export, choose the source that best matches the question you need to answer. Use PDF comparison where page-level visual changes matter.

3. Run one comparison

Open Document Compare

Do not create repeated jobs while the first result is still running.

4. Review every detected change in context

Read the full sentence, surrounding clause, related definitions, cross-references, schedules and appendices. For PDFs, inspect the highlighted region and surrounding page.

5. Separate technical evidence from legal significance

Document Compare can help answer:

  • what changed;
  • where a visual difference occurred;
  • what deserves review.

It cannot safely answer:

  • whether a change is legally valid;
  • which version controls;
  • whether a clause is enforceable;
  • whether a change creates an unacceptable risk.

6. Record review decisions separately

For important agreements, record accepted changes, rejected changes, questions, clauses needing legal review, and the version approved for signature.

7. Recompare after major edits

When another revision arrives, compare it against the correct approved baseline rather than relying on memory.

Practical checklist

  1. Confirm the authoritative pair.
  2. Keep originals unchanged.
  3. Compare supported versions.
  4. Review each change in context.
  5. Check high-risk clauses manually.
  6. Record decisions separately.
  7. Repeat against the correct baseline after another revision.

For tool instructions, see /help/document-compare.

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