Compare PDF Diff & Revisions
Compare two PDF documents side-by-side to highlight added and removed text with 100% in-browser privacy.
How to Compare Two PDF Files Online
AWSM Tools Compare PDF enables immediate identification of contract clauses, revision changes, price alterations, and draft additions. Both files are analyzed in local device memory with zero server uploads and total privacy.
Step-by-Step Instructions
- Select Files: Click Browse A to load the original PDF and Browse B to load the revised document. You can also explore immediate features with Try Sample Comparison.
- Review Diff Highlights: Green highlighted text indicates additions in Document B; red struck-through text shows terms deleted from Document A.
- Navigate Pages: Use the page controls to inspect multi-page documents synchronized side-by-side.
Technical Reference & Specification Matrix
| Technical Parameter | Standard Compliance | Engine Implementation |
|---|---|---|
| Diffing Algorithm | Myers / Longest Common Subsequence (LCS) | Word-level lexical alignment with inline styling |
| Parsing Engine | PDF.js W3C Web Worker | High-fidelity text content stream extraction |
| Client Privacy | Zero Server Telemetry | 100% In-browser memory execution; documents never leave device |
Frequently Asked Questions
The engine extracts text streams from each page using PDF.js and runs an optimized longest common subsequence (LCS) diff algorithm. Additions are styled in green, while deletions are struck through in red.
Never. Both documents are parsed and diffed entirely inside your device RAM using client-side JavaScript. No file or text content is ever transmitted across the internet.
Yes. The tool automatically synchronizes navigation up to the maximum page count of the two files, allowing you to review changes page-by-page.
Yes. The Progressive Web App Service Worker permanently caches the comparison engine. You can compare sensitive agreements completely offline.