Compare PDF
Show differences between two PDFs side by side and highlight changes.
First PDF (Original)
PDF or image files supported
Second PDF (Revised)
PDF or image files supported
Compare two PDFs side by side
See exactly what changed between two versions of a document — page order, additions, deletions, and edited text.
Compare PDF opens two files next to each other and highlights the differences page by page. It's the fastest way to check a signed contract against the one you sent, spot what a legal reviewer changed in your MSA, or verify that a new PDF export matches the reference you approved last month. No manual scrolling, no eye strain.
The tool works on text-based PDFs — the ones you can select and copy from. If your PDF is a scan (an image of text), run OCR PDF on it first so Compare has real characters to diff. For pixel-level image diffs, use the visual overlay mode which highlights layout changes even when the underlying text is identical.
How to use it
- 1Upload the original PDF as file 1.
- 2Upload the revised PDF as file 2.
- 3The tool renders both PDFs side by side and computes a difference map per page.
- 4Scroll through the pages — added text is highlighted in green, removed text in red, edited regions in amber.
- 5Use the page toggle to jump directly to pages that contain differences.
- 6Optional: export a comparison report as a new PDF for the record.
Real-world use cases
- Verify that a returned signed contract has not been silently edited before signing.
- See exactly what a legal team changed between MSA drafts, page by page.
- Confirm a new report export matches the version you approved for print.
- Compare invoice runs to spot line-item changes month over month.
- Audit template changes: diff last quarter's proposal template against the current one.
Supported formats & limits
Input: two PDFs of comparable structure (text-based preferred). Output: an on-screen diff view and an optional comparison-report PDF.
Privacy
Your uploaded file is written to a temporary folder on our server, processed, and deleted by the operating system as soon as the request finishes — typically within seconds. Nothing is stored in our database. Traffic is encrypted over HTTPS.
Full details in the Privacy Policy.
Frequently asked questions
Does Compare PDF work on scanned documents?▾
Not directly — scans are images, so there is no text layer to diff. Run OCR PDF on both files first, then compare the OCR'd copies. For pixel-level layout comparison of scans, switch to visual overlay mode.
What if the two PDFs have a different number of pages?▾
Extra pages in either file are shown as fully added / fully removed on the diff. The comparison still runs on the pages that exist in both files.
Are formatting-only changes flagged?▾
Compare focuses on textual content by default. Font, colour or spacing changes that don't alter the readable text are ignored unless you enable visual overlay mode.
Can I export the diff as a report?▾
Yes — save a comparison report PDF that highlights every changed region page by page. Useful for legal audit trails or client sign-offs.
Is my data private?▾
Yes. Both uploaded PDFs are processed in memory and deleted from the server as soon as the request finishes. Nothing is stored in our database.