Does this tool highlight differences between the two PDFs automatically?

The tool provides a visual side-by-side view with synchronized navigation. For pixel-level diff highlighting, enable the Overlay Diff mode which blends both pages using canvas compositing to highlight areas that differ between the two documents.

Are the PDF files uploaded to any server for comparison?

No. Both PDFs are rendered locally inside your browser using pdf.js. No file data is transmitted to any server at any point.

Compare PDF Files Side by Side Online Free

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PDF A — Original

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PDF B — Revised

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Visual PDF Difference Detection & Synchronized Navigation

Comparing contracts, policy documents, statements, and research revisions requires seeing changes in layout, wording, and tables immediately. GS DocSeva renders both PDFs locally using WebAssembly/Canvas rendering, allowing you to advance through pages together or use mathematical difference blending to detect modified text instantly without transmitting files to any external servers.