Compare Two PDF Documents for Differences

Our PDF comparison tool detects all text-level changes between two documents, including additions, deletions, and modifications. It highlights added text in green, removed text in red, and modified sections with clear annotations. The tool also detects changes in headings, paragraphs, lists, and basic formatting. For best results, compare text-based PDFs rather than scanned documents.

For scanned PDFs, we recommend running OCR on both documents first using our OCR PDF tool. Once both versions have a searchable text layer, the comparison tool can identify differences between them. Without OCR, the tool would compare the raw images, which is less precise for text changes. Running OCR first ensures accurate, word-level difference detection.

Upload both versions of your PDF — the original and the revised version. The tool analyzes the text content page by page, comparing the two documents line by line. Differences are highlighted visually: green for content that was added, red for content that was removed, and yellow for modified sections. You can review each change individually and download a detailed comparison report.

There is no artificial file size limit because all processing happens locally in your browser. The only constraint is your device's available memory. Most documents up to several hundred pages compare smoothly on modern computers. Unlike cloud-based comparison tools that often cap file sizes at 10-20MB, our client-side approach handles large documents without upload delays.