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✓ 100% Free🔒 Files Stay On Device✦ Overlay Blend Mode

Compare PDFs Spot Differences Instantly

View two PDF versions side by side with synchronized scrolling. Or use overlay mode to blend both documents. Free, no upload.

VERSION 1 — ORIGINAL
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Drop Version 1 here

Original / before

0 / 1 filesMax 200MB per file
VERSION 2 — REVISED
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Drop Version 2 here

Revised / after

0 / 1 filesMax 200MB per file

How to Compare Two PDF Files Online — Free

Upload both PDFs and instantly view them side by side with synchronized scrolling. Use overlay mode to blend the documents and see differences at a glance.

Side by side vs overlay — which view to use

Side by side is best for reading content differences — you can see exactly what text changed between versions. Overlay mode is best for spotting visual and layout changes — moving the blend slider back and forth reveals shifted elements, changed margins, or moved sections instantly.

Compare contract versions before signing

Upload the original and revised contract side by side. Navigate to sections you care about and zoom in to read changes clearly. Both documents render entirely in your browser — nothing is sent to a server.

Compare PDFs on iPhone and Android

Compare PDFs works on all devices. Open in Safari on iPhone or Chrome on Android, upload both documents from Files or Google Drive, and compare them on your phone screen.

Frequently Asked Questions

The tool renders both documents visually so you can spot differences by sight. In overlay mode, differences appear as ghosted areas when you move the slider. Automatic text diff highlighting is not currently supported.
No — both PDFs are rendered entirely in your browser using pdfjs-dist (WebAssembly). No files are transmitted to any server. Documents stay private on your device.
Yes — if the documents have different page counts, the shorter document shows a blank panel for pages that don't exist. Navigation always goes up to the maximum page count of either document.
Overlay mode blends both documents on top of each other. Use the slider to adjust opacity from 0% (only Version 1) to 100% (only Version 2). Moving the slider back and forth makes visual differences immediately apparent.
Use side-by-side mode to read content differences, and overlay mode to spot layout and formatting changes. Navigate page by page and zoom in on sections of interest.
Yes — use the zoom controls in the toolbar to zoom in and out. Both panels zoom in sync in side-by-side mode.