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Compare PDF — Visual PDF Comparison Tool Online Free

Compare two PDF files side by side online for free. Spot every difference with overlay, side-by-side, and pixel-diff modes — no software needed.

Upload Two PDFs to Compare

Original PDF

Comparing PDF

Why Compare PDFs with PanaPDF?

Side-by-Side Comparison

Compare two PDF files page by page in a clear side-by-side layout. Instantly see content differences between the original and modified documents

Overlay Comparison Mode

Stack two PDFs on top of each other with adjustable opacity. Slide the transparency to reveal exactly where changes were made between versions

Pixel-Level Difference Detection

Automatically detect every visual difference between two PDF documents. Changed pixels are highlighted in red so you never miss a single edit

100% Browser-Based Privacy

Your PDF files never leave your device. All comparison processing happens locally in your browser — no uploads, no data stored, complete privacy guaranteed

How to Compare Two PDFs Online

Find every difference between two PDF documents in 4 simple steps — completely free

1

Upload Both PDFs

Upload the original PDF and the modified version. Drag and drop or click to browse — supports files up to 100 MB each

2

Choose Comparison Mode

Select Side by Side for a clear dual-pane view, Overlay to stack documents, or Difference to auto-detect pixel-level changes

3

Navigate & Inspect

Browse through pages using navigation controls. Zoom in on specific areas and use overlay opacity to pinpoint exact differences

4

Review All Changes

The diff mode shows a percentage of changed pixels per page, helping you quantify exactly how much has been modified between versions

Perfect for Every Workflow

Compare PDF documents to verify edits, track changes, and ensure document accuracy across revisions

Legal & Contract Review

Compare PDF contracts, agreements, and legal documents to verify that only agreed-upon changes were made between drafts. Catch unauthorized modifications instantly

Design & Publishing

Compare PDF proofs, layouts, and design files to spot visual differences. Verify that revisions match the requested changes before final production

Quality Assurance

Compare PDF reports, manuals, and documentation to ensure updates were applied correctly. Identify unintended changes across document versions

Trusted by:

  • Lawyers reviewing contract revisions
  • Editors checking document updates
  • Designers verifying layout changes
  • QA teams auditing document versions

The Easiest Way to Compare PDF Files Online Free

Need to find differences between two PDFs? PanaPDF lets you compare PDF documents visually — side by side, overlaid, or with automatic pixel-level difference detection — directly in your browser. Upload two PDFs, navigate page by page, and see every change highlighted instantly. Completely free, no account required, and your files never leave your device.

Compare PDFs online — works entirely in your browser

Three comparison modes: side-by-side, overlay, and diff

100% private — files never uploaded to any server

Supports all PDF documents up to 100 MB

Compare PDFs Free On Any Device

Find differences between PDF documents using any modern web browser — desktop, tablet, or phone

Mobile Friendly

Compare PDF files on iPhone, Android, or iPad. The responsive interface adapts to your screen for easy mobile document comparison

Desktop Optimized

Full-featured PDF comparison tool for Windows, Mac, and Linux. Side-by-side mode works best on wider screens for maximum detail

Cross-Platform

Works on Chrome, Firefox, Safari, and Edge. Compare PDF documents from any operating system, anywhere

Frequently Asked Questions

Everything you need to know about comparing PDF documents online

Upload both PDF files to PanaPDF — the original and the modified version. Choose your comparison mode (side-by-side, overlay, or difference), then navigate page by page to spot all changes. It's completely free with no account required.
PanaPDF offers three modes: Side by Side shows both PDFs in a dual-pane layout, Overlay stacks them with adjustable opacity, and Difference automatically highlights changed pixels in red with a percentage score.
Yes. All processing happens entirely in your browser. Your PDF files never leave your device — nothing is uploaded to any server. Your privacy is 100% protected.
Yes. PanaPDF handles PDFs with different page counts. Pages that exist in one PDF but not the other are shown as missing, so you can identify added or removed pages.
In Difference mode, PanaPDF compares every pixel between the two pages and calculates what percentage of pixels are different. This gives you a precise measure of how much has changed on each page.
Each PDF can be up to 100 MB. There is no limit on the number of pages. Both files are processed entirely in your browser, so performance depends on your device.

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