How to compare two versions of a PDF
You don't need to read both documents line by line — let AI tell you what changed and what matters.
Updated July 5, 2026
Do it now with AI Compare — free, no signup. Open →Why a semantic compare beats a text diff
A character-level diff lights up on every reflowed line and reformatted heading, drowning the changes that matter in noise. When you’re checking what really changed between two versions of a contract, invoice, or policy, you want the substance: a changed amount, a moved deadline, an altered clause — not that a paragraph wrapped differently.
How Pditor does it
Add both PDFs and the AI reads them as documents, not as raw text streams. It reports the substantive edits, calls out numerical and date changes specifically (the ones that most often carry legal or financial weight), and rates how significant each change is — delivered as a clean Markdown report you can save or share.
Private and free
The compare runs through Pditor’s AI pipeline, provider calls opt out of training, and your files auto-delete within an hour. It’s free to try, with higher limits on Pro.
Frequently asked questions
- How do I compare two PDF documents?
- Add both versions to the AI Compare tool. It reads them and returns a semantic diff — the substantive, numerical, and date changes that matter — as a report. Free to try, no signup to start.
- How is this different from a normal text diff?
- A plain diff flags every character change, including reflowed formatting. The AI compare focuses on meaning — it surfaces the edits that actually change the document, and rates their significance.
- Can it compare two contracts?
- Yes — that's a common use. It highlights changed clauses, amounts, dates, and terms so you don't have to read both versions in full.
- Are my documents private?
- Provider calls opt out of training and prompt/response pairs aren't kept beyond a short cache. Files auto-delete within an hour.