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Falcon Pdf

Compare · In your browser

See what changed. Without sending either version away.

Falcon Compare is a PDF diff tool that compares two versions of a document pixel-by-pixel. The output is a single file where every changed region is outlined in red and added or removed pages are flagged. Both inputs stay on your computer.

Both PDFs open in this tab. The pixel-by-pixel diff is computed on your computer; the diff report is written here. By design.

Browser-only · no upload · Updated 2026-05-28

Pixel-level diff. Cosmetic re-renders (font hinting, AA) may show as faint changes.

Why this tool exists

Comparing two versions of a document is the kind of work that happens on contracts, agreements, and revisions of things that exist for legal reasons. The original and the revised are the most sensitive pair of files on the laptop that day. Uploading both to a comparison tool is the most sensitive double-upload of the year.

When the comparison runs on your computer, neither version leaves. Both PDFs open in this tab. Each pixel is compared on your machine. The diff report — the document that says “this changed, this did not” — is written here. The two versions are not joined by a third copy somewhere else.

Original (A)

Drop a PDF here

or

Updated (B)

Drop a PDF here

or

Step-by-step

How to use Falcon Compare

Falcon Compare is a PDF diff tool that compares two versions of a document pixel-by-pixel. The output is a single file where every changed region is outlined in red and added or removed pages are flagged. Both inputs stay on your computer.

  1. 01

    Open the original PDF and the revised PDF.

  2. 02

    Start the comparison.

  3. 03

    Review the diff — changed regions are outlined in red, added/removed pages flagged.

  4. 04

    Save — the diff report is written to a PDF, then download.

Updated 2026-05-28

FAQ

Common questions

Are my two files uploaded to be compared?

No. Both documents open in this browser tab and the comparison runs on your computer. Two drafts of the same confidential agreement can be checked against each other without either leaving your device.

How does it show me what changed?

It compares the two versions pixel by pixel and produces a single file where every changed region is outlined in red, with whole pages flagged where one version has added or removed them. You see the differences at a glance.

Does it compare the words or the appearance?

The appearance. Because the check is visual, it catches any change you can see — wording, but also moved paragraphs, swapped figures, and shifts in layout that a text-only comparison would miss.

Can it handle versions with different page counts?

Yes. Where one version has pages the other does not, those pages are flagged as added or removed, so a comparison still makes sense even when the documents are not the same length.

How your file stays private

No upload

Opens, parses, rewrites on your device. Nothing about the contents transits a Falcon server.

Zero logs

No filenames, sizes, contents, or per-file telemetry. Operation counts only.

No trackers

Open the Network tab during use. Only first-party JS appears in the request log.

Metadata stripped

Authors, edit history, EXIF, and embedded thumbnails are removed alongside the visible content.

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