Guide · AI
How to compare two contract versions and explain the changes
Reviewed
Short answer
To compare two versions of a contract, put the original and the revised PDF side by side in a comparison tool that lists every changed passage with its before and after text and page numbers, then read the changes that matter most — term, fees, dates, liability, termination and governing law. PDFBetter's AI compare PDF computes that change list without AI and adds a plain-language explanation of each change for 3 AI credits. It's a review aid, not legal advice.
On this page (5)
Step by step
- 1
Add both versions
Open AI compare PDF. Drop the original on the left and the revised version on the right, or pick two documents from your account.
- 2
Scan the word diff
Added and removed words are highlighted page by page in your browser, free.
- 3
Explain changes
With a free account, the factual change list is computed on our servers and the AI groups and explains it. If you're out of credits, you still get the facts.
- 4
Read the facts first
“Changes (facts)” lists each changed, added, removed or moved passage with the exact before and after text and the page in each version; “Changed figures” pulls out amounts, percentages, dates and durations.
- 5
Then read the explanations
Each card explains one change in plain language with a low, medium or high materiality hint, and lists the quotes it relies on.
1Two versions
2Compare them
3Changes marked
What to check in a revised contract
Start with numbers and time: fees, caps, notice periods, terms and renewal dates are where “minor edits” hide. Then look at who must do what: a “may” that became “shall”, a new obligation, a removed exception. Finally check termination rights, liability limits, indemnities and governing law.
A moved paragraph is reported as moved, not deleted and re-added, so reordering doesn't bury real changes.
What it can't see
Only text is compared. Changes to images, signatures, stamps and layout aren't explained, although the visual diff can show them. Scanned versions need OCR first, and OCR misreads can look like changes. Word files must be converted to PDF first.
The AI explanation can misread intent or miss why a change matters. Check every card against its quotes and ask a lawyer when the stakes are high.
Tools used in this guide
- AI compare PDF versionsAdd the old and new version: get the exact before/after text with page numbers, plus an AI explanation you can check against it.
- Compare PDFAdd the old and new versions, and see every word that was added or removed, highlighted side by side.
- OCR PDFUpload a scan, pick its language, and download a PDF that looks the same but lets you search, select and copy the text.
- Word to PDFTurn a Word document into a PDF that looks the same on every device.
Questions people ask
Is the change list itself made by AI?
No. The list of changed passages, page numbers and changed figures is computed from the text of both PDFs. Only the grouping and plain-language explanation use AI.
Can I compare two saved versions of the same document?
Yes. Pick one document and two of its saved versions, or ask a connected agent to compare two revisions.
What if the counterparty sent a Word file?
Convert it with Word to PDF first, then compare it with your PDF. Formatting differences between the two files don't show up as text changes.
Does it work for documents other than contracts?
Yes — policies, price lists, terms of service, specifications or any document that comes in versions.
Is the explanation legal advice?
No. It is a reading aid. PDFBetter is not a law firm.