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100% Private In-Browser Tool • Zero Uploads

Compare PDF Documents Online

Instantly spot visual, textual, and layout differences between two PDF versions directly in your browser.

Compare PDF Documents

Compare two versions of a PDF side-by-side with interactive split slider, pixel diff heatmap, and text change analysis.

Upload two versions of a PDF (e.g. V1 Original and V2 Revised). Both documents are rendered completely in your browser without transmitting data to any server.
AOriginal Document (V1)

Drag & drop image files here, or browse

Select or drop original PDF (Document A)

BRevised Document (V2)

Drag & drop image files here, or browse

Select or drop modified PDF (Document B)

Step-by-Step Guide

How to use Compare PDF Documents Online

1

Upload Both PDFs

Select or drop your Original Document (Document A) and Revised Document (Document B).

2

Choose Comparison Mode

Switch between Side-by-Side, Slider Split, Visual Diff, or Text Diff modes.

3

Inspect Differences

Navigate through pages, zoom in to examine pixel changes, and review textual modifications.

Features & Benefits

Why use ImgZero for Compare PDF Documents Online?

Side-by-side synchronized view with linked navigation and zoom controls
Interactive overlay Before/After split slider to inspect subtle layout shifts
Visual pixel diffing highlighting additions in green, deletions in red, and changes in amber
Myers line-by-line textual diff algorithm displaying exact textual additions and deletions
100% client-side execution — both documents remain strictly in your browser memory

Frequently Asked Questions

How does the visual pixel diff work?

ImgZero renders corresponding pages of both documents to high-resolution HTML5 canvases and calculates per-pixel delta values. Additions, deletions, and modifications are highlighted in distinct colors.

Can I compare PDFs with different numbers of pages?

Yes. You can freely navigate through all pages of both documents. If one document has fewer pages, the tool clearly indicates that the page does not exist in that version.

Are my sensitive contracts or documents uploaded to any server?

No. Comparison is executed 100% locally in your browser using pdfjs-dist and Canvas rendering. Zero bytes ever leave your device.

100% Client-Side Privacy Guarantee

Your files stay on your machine. No server uploads and no file-content tracking.

Zero Server Bandwidth Delay
Instant Web Worker Speed
Works Fully Offline

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