Compare two PDFs

Pick two versions of a PDF (a contract before and after edits, two exports of a report, last month's and this month's invoice) and see every word that changed: removed text in red, added text in green, with the page it's on. Line breaks and page breaks are ignored, so text that only reflowed doesn't count as a change. Free, and your files never leave your browser.

PDF A (original)
PDF B (changed)

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Pick two PDFs, or drop them on this box (the first fills A, the next B).

Differences

Add both PDFs to compare them.

How it works

Both PDFs are read by pdf.js, the PDF engine built into Firefox, and their text is rebuilt line by line from the position of each piece of text on the page (the same extraction as PDF to text). The two texts are compared in two passes: first line by line, to find the blocks that differ, then word by word inside each block, so a one-word edit shows as one word, not a whole changed paragraph. Spaces, line breaks and page breaks are normalized first: if an edit pushes text onto the next line or the next page, only the edit itself shows up.

What it does and doesn't compare

Change	Detected?
Words added, removed or replaced	Yes, word by word, with page numbers in both files.
Numbers, dates, amounts	Yes: they are words too, so "€1,200" → "€1,250" shows up.
Text that only moved to another line or page	Ignored on purpose. Reflowed text is not a change in content.
Fonts, colors, images, layout	No: only the text is compared. Turn both into images with PDF to image, then use compare images for a pixel diff.
Scanned PDFs	No: scans have no text layer. Run OCR on them first.

Automate it: diff PDFs you generate

If your app makes PDFs (invoices, reports, tickets) from HTML, a text diff between the output before and after a template change is a cheap regression test: render both versions with the Shotmint API, extract the text with pdftotext (poppler), and diff it.

curl "https://shotmint.creasework.com/v1/pdf?url=https://staging.example.com/invoice/42&format=A4" -H "X-API-Key: YOUR_KEY" -o new.pdf
pdftotext -layout old.pdf old.txt && pdftotext -layout new.pdf new.txt
diff -u old.txt new.txt

Each render is 1 credit. €5 buys 2,000 with no subscription, and credits never expire. More in the API docs and the guides.

Get 25 free renders a month Try HTML to PDF

FAQ

Are my PDFs uploaded? No. Both files are read and compared by JavaScript on this page, so contracts and statements stay on your device.

Can I compare a Word document with a PDF? Save or print the Word document as PDF first, then compare the two PDFs.

Why does a whole paragraph show as changed? When most words in a block differ, it's clearer to show the old and new block whole. It also happens when one file's text is in a different order (for example, two-column layouts extracted differently).

Is there a size limit? No limit and no signup. Very long documents with very many changes may take a few seconds; if the files are almost completely different, the tool says so instead of listing every word.

Compare two PDFs

Differences

How it works

What it does and doesn't compare

Automate it: diff PDFs you generate

FAQ

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