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Compare PDFs

Two versions of a document; a report of what changed, word by word.

More free conversions, where you upload. The Fylane extension does the same work inside any upload form, on its own free share every day.About the extension

How to compare PDFs

  1. Drop the two PDFs, old first.
  2. Nothing to choose.
  3. Press Compare and open the report.

What happens to your file

Both PDFs’ text layers are read; paragraphs are matched between the two, and inside each changed paragraph the words are compared — additions marked green, removals red — in a standalone HTML page that opens in any browser and prints. The header counts the words added, removed and unchanged, and how alike the two are.

Text only: layout, images, fonts and page breaks are not compared, and a paragraph that moved reads as removed in one place and added in another. A scanned PDF has no text layer — run OCR PDF on it first.

Questions

Which file goes first?

The older one. Then “added” means added in the newer version. Swap them and the colours swap.

Does it compare formatting?

No — words. A changed font, margin or bold does not show; a changed word does. That is what most version questions are about.

They came out 100% the same?

Then the text is the same. Differences in layout or pictures are not measured here.

Do this in code

curl -X POST https://api.fylane.dev/v1/jobs \
  -H "Authorization: Bearer $FYLANE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "file_id": "<file id>",
    "operation": "pdf.compare",
    "options": {
      "file_ids": [
        "<second file id>"
      ]
    }
  }'

The same operation, pdf.compare — Two PDFs’ text compared — paragraphs aligned, words added and removed marked in an HTML report, with counts and a similarity; text only, scans sent to OCR first. Upload first with the quickstart; every option is on the operations page. 500 free credits a month, then $5 per thousand.