Compare PDF Files: Free Online PDF Comparison Tool
Find differences between two PDF documents side by side — 100% private, all in your browser.
Comparing PDF documents for changes, revisions, or inconsistencies is essential for contract reviews, document version control, and quality assurance. Our PDF comparison tool allows you to upload two PDF files and identify differences in text content. The tool extracts text from both documents and highlights additions, removals, and modifications. Perfect for reviewing contract changes, comparing document versions, or verifying edits. The entire comparison happens locally in your browser — no files are uploaded to any server, ensuring complete privacy for your sensitive documents.
🔒 100% Client-Side Processing
📄 Compare Two PDFs
🔍 Text-Based Difference Detection
✅ Highlight Additions & Removals
📊 Side-by-Side Analysis
💾 Download Comparison Report
🆓 Completely Free
💡 How it works: Upload two PDF files (Original and Revised), click "Compare PDFs", and view the differences. Added text appears in green, removed text appears in red with strikethrough. Perfect for contract reviews, version control, and document verification.
📊 Compare PDF Files
Upload two PDFs to find differences in text content.
📄 Original Document
Click or drag PDF
✖ Remove
🔄 Revised Document
Click or drag PDF
✖ Remove
📊 Comparison Results
Frequently Asked Questions about PDF Comparison
How does PDF comparison work?
Our tool extracts text from both PDF files using PDF.js, then performs a text-based comparison. It identifies lines that are identical, lines that were added, and lines that were removed. The differences are highlighted with color coding for easy review.
What types of differences can be detected?
The tool detects text additions, deletions, and modifications. Added text appears with a green background, removed text appears with a red background and strikethrough. Identical text appears in normal formatting.
Will this detect formatting changes?
This tool focuses on text content differences. Formatting changes (font size, color, layout) are not detected. For comprehensive formatting comparison, specialized PDF comparison software may be needed.
Is my document secure during comparison?
Absolutely! The entire comparison process happens locally in your browser using PDF.js. Your PDF files never leave your computer — no uploads to any server. This ensures complete privacy for your sensitive documents.
Can I compare password-protected PDFs?
Currently, password-protected PDFs cannot be processed. You'll need to unlock the PDF first using an unlock tool before comparison.
What about scanned/image-based PDFs?
Scanned PDFs (image-based) do not contain selectable text. For best results, use OCR (Optical Character Recognition) to convert them to text-based PDFs before comparison.
Will this work on mobile devices?
Yes! The tool is fully responsive and works on smartphones and tablets. The two-panel layout adapts to smaller screens for easy file selection.