Compare PDF Online Free: PDF Diff Checker
Upload two PDF files and see text differences. No uploads, works offline.
Drop or browse
Drop or browse
How to Compare PDF Files
Drop two PDF files into the upload zones above. Click Compare PDFs. The tool extracts text from each PDF, computes a line-by-line diff, and highlights differences. Download the diff report as text.
What Differences Are Detected
Text differences are detected line by line. Green lines are added in PDF B. Red lines are removed from PDF A. Yellow lines are changed. The diff report can be downloaded as a text file for documentation.
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Frequently Asked Questions
How does PDF comparison work?
Upload two PDF files. The tool extracts text from each using pdf.js, then computes a line-by-line diff. Differences are highlighted in the output. You can download the diff report as text.
Do you upload my PDFs?
No. All comparison happens in your browser. Your PDF files are read locally using File API and never sent to any server.
What types of differences are detected?
Text differences are detected line by line. Added lines, removed lines, and changed lines are highlighted. Image and layout differences are not detected.
Can I compare scanned PDFs?
Scanned PDFs without a text layer cannot be compared. The tool requires PDFs with selectable text. Use OCR tools first for scanned documents.
Is there a file size limit?
No hard limit. Very large PDFs may take longer to process. The tool runs entirely in your browser.
Can I download the diff report?
Yes. After comparison, you can download the diff report as a text file showing all added, removed, and changed lines.