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PDF Diff Checker

Compare an original PDF with a revised version and download annotated copies where added, deleted, and changed words are highlighted directly on the pages.

Green

Added text in the modified PDF

Red

Removed text in the original PDF

Orange

Changed or replaced words

Browser-based PDF comparison

This MVP extracts selectable PDF text, keeps approximate word positions, compares words page by page, and writes highlight overlays into new downloadable PDFs.

Files stay local in your browser.

Best for text-based PDFs, manuscripts, reports, and assignments.

Scanned PDFs need OCR before reliable comparison.

Upload PDFs

Choose the original document and the revised document.

1. Original PDF

Upload original PDF

The older version or submitted draft

2. Modified PDF

Upload modified PDF

The newer version or revised draft

Ignore caseTreat Research and research as the same word.Ignore punctuationUseful when commas, periods, or quotation marks changed but wording did not.

Processed Locally

Your file never leaves your device. Everything is processed in your browser — we never see or store your data.

Frequently Asked Questions

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