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Compare two PDFs and highlight differences — 100% private, no upload.
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Compare two PDFs and highlight differences — 100% private, no upload.
Compare two PDF files instantly and see exactly what changed — highlighted directly on the page. Works entirely in your browser. Your files never leave your device.
The Diff mode renders both PDFs at the same scale and compares every pixel. Pixels that differ by more than a small threshold are highlighted in red. Unchanged pixels are shown in greyscale so the red highlights pop out. Each page card also shows a "% changed" badge — useful for spotting which pages were edited.
If the two PDFs have different numbers of pages, PDFree compares all pages that exist in both files. Pages that only appear in one PDF are shown with an "Only in A" or "Only in B" badge.
PDF comparison often involves confidential documents — legal agreements, financial reports, draft contracts. With PDFree, nothing is ever uploaded. All rendering and pixel comparison happens inside your browser tab using PDF.js. No server ever receives your files.
Never. All processing happens inside your browser. Your PDFs never leave your device.
Yes. PDFree compares pages that exist in both files. Pages that only appear in one PDF are shown with a badge indicating which document they belong to.
Yes, completely free. No subscription, no premium tier, no per-file charges. PDFree is open-source and runs entirely in your browser.
This tool performs a pixel-level visual comparison — it shows any visible difference, whether from text edits, formatting changes, added images, or layout shifts. For text-only diff, use a dedicated text-diff tool after extracting text.