PDF Version Diff

Compare text content between two PDF versions free online. Extracts text from both PDFs using pdf.js and shows a real line-by-line diff of what changed.

PDF A

PDF B

Browser only -- uses pdf.js, no upload to any server.

How to Use This Tool

Upload both PDF versionsA and B

Click Compare TextExtracts text via pdf.js

Review the line diffSee exactly what text changed

Real Text Extraction via pdf.js, Then a Real Diff

This uses pdf.js -- the same open-source library powering Firefox's built-in PDF viewer -- to genuinely parse each PDF's internal structure and extract its actual text content, entirely in your browser. The extracted text from both versions then goes through a real line-by-line diff comparison.

Text Comparison, Not Visual Comparison

This deliberately compares text content only, not visual layout or formatting -- two PDFs that look completely different visually but contain the same text would show no differences here, since the comparison happens at the extracted-text level, not the rendered-page level.

Why Scanned PDFs Won't Work

A scanned document saved as a PDF is fundamentally just embedded images with no underlying text layer to extract -- this tool needs actual text content to compare, so scanned-image PDFs simply have nothing extractable to work with.

Frequently Asked Questions

Using pdf.js, the open-source PDF rendering library originally built for Firefox's built-in PDF viewer -- it parses the PDF's internal structure and extracts the actual text content, all running client-side in your browser.

Text content only -- this extracts and compares the actual text from both PDFs, not visual layout, formatting, images, or positioning. Two PDFs with identical text but different visual designs would show as having no differences.

PDF text extraction order depends on the document's internal structure, which doesn't always match visual reading order, especially for PDFs with complex layouts, multiple columns, or tables -- a known limitation of text extraction from PDF's underlying format.

Scanned PDFs stored as images have no extractable text layer at all, so this tool can't meaningfully compare them -- text extraction only works for PDFs with actual embedded text content, not image-based scans.

Checking what text changed between two contract drafts, comparing report revisions, or verifying that a regenerated PDF's content matches an expected previous version.