Compare PDF Files Online

Compare two PDFs directly in your browser — visual pixel diff, word-level text diff, and synchronized scroll. Zero upload.

🔒 100% Client-Side ☁️ No Upload ⚡ Web Worker

Original PDF

Drag & drop or click to select
Original / reference document

Modified PDF

Drag & drop or click to select
Updated / modified document
10%
OCR runs locally — may be slower.

Files stay on your device.

Comparing…
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Original
Modified
Analysis
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    How to compare PDF files online

    1. Upload your Original PDF to the left card.
    2. Upload your Modified PDF to the right card.
    3. Adjust the Sensitivity slider if needed.
    4. Click Compare PDFs and wait for the analysis.
    5. Scroll both panels in sync, browse thumbnails, and use the right sidebar to view Text diff, Overlay or Report.

    Features

    Synchronized Scroll
    Both panels scroll together for effortless comparison.
    Visual Pixel Diff
    Pixel-level diff overlay via pixelmatch Web Worker.
    Word-level Text Diff
    Highlights added / removed words with jsdiff.
    Overlay Mode
    Blend both pages with adjustable opacity and blend mode.
    Page Thumbnails
    Click any thumbnail to jump straight to that page.
    100% Private
    All processing in your browser. Zero upload, zero storage.

    Frequently Asked Questions

    No. Your files never leave your device. All processing runs entirely in your browser.

    Yes. Enable OCR for scanned PDFs before clicking Compare. Tesseract.js extracts text from images locally.

    When Sync scroll is enabled, scrolling either panel automatically mirrors the position in the other panel proportionally.
    Is my PDF safe?
    This tool processes PDFs locally in your browser. We never receive, store or transmit your documents.