See What Changed Between Two PDFs

TL;DR: PDF Compare is a free online tool that highlights the differences between two PDF files — edited text, formatting, and swapped images — right in your browser, no signup, nothing uploaded.Great for checking a revised contract or proposal, two versions of a report, or a re-exported document.

Start Comparing PDFs…
Screenshot of PDF Compare
Christopher Atlan

Built by Christopher Atlan at Leitmotif GmbH. Making file-comparison tools since 2020 — building software for over 18 years. diff.tools is one idea: a focused tool for each format, with results you can hand from one tool to the next.

A quick tour

  1. Every change, found and listed

    Drop two PDFs and read the result like a document: pages side by side with every difference highlighted, and a change list that walks you through them one by one.

    Two versions of a proposal PDF side by side with the differences highlighted and a change list on the left
    Two revisions of a proposal — every edit highlighted in place.

  2. More than text edits

    Formatting-only changes get their own cards naming what changed — font, size, or color. Replaced images are detected too, shown old-next-to-new and classified as visually similar when only the details moved.

    Change cards: a replaced logo image shown old next to new, plus word-level text replacements

  3. Compare only the pages you need

    A 200-page manual against a revised chapter? Pick exactly which pages take part in the comparison and leave the rest out.

    Page selection strip above the documents: select pages to compare, all, none, compare selected

  4. Scanned PDFs? Run OCR

    When a PDF has no text layer — a scan or a fax — run the built-in text recognition and compare the result. Like everything else, OCR runs locally in your browser.

  5. From PDF to pure text

    Need a classic line-by-line diff? Open the extracted text of both PDFs in Text Compare with one click — page breaks and reading order preserved.

    The extracted text of both PDFs opened in Text Compare as a side-by-side diff
    The same pair as a plain text diff, one click later.

How to compare two PDF files?

  1. Open the web app: Launch the free PDF comparison tool in Google Chrome or Microsoft Edge.

    Start Comparing…

  2. Pick your PDF Documents: Click the Choose PDF A button and find the first PDF file you want to compare. Repeat for the second PDF file with Choose PDF B.

  3. Review the Results: Processing happens instantly and locally. Any text changes or visual differences between the two pages will be clearly highlighted for you to review.

Frequently asked questions

  1. Can I compare two PDFs for differences?

    Yes — pick two PDF files and every difference is found for you: edited text, formatting changes, and replaced images, highlighted side by side with a change list to step through.

  2. Can I compare only some pages?

    Yes. Select exactly which pages take part in the comparison — useful when a short addendum meets a long manual.

  3. Can I compare scanned PDFs?

    Yes. If a PDF has no text layer, run the built-in OCR to recognize the text first — it runs locally in your browser, like the comparison itself.

  4. Are my files uploaded?

    No. The comparison runs entirely in your browser; file contents never leave your device.

  5. Can it edit or merge PDFs?

    No — it's deliberately a viewer. It shows you the differences; it never touches your files.

  6. How are PDFs compared?

    The text is extracted in reading order and compared word by word, across page boundaries. Formatting and embedded images are compared too, and the rendered pages are shown side by side with all changes highlighted.

  7. Which browsers are supported?

    Google Chrome and Microsoft Edge.

Requirements

Google Chrome or Microsoft Edge

Privacy & Data Processing

Privacy and security aren't just something you should hope for — they're something you should expect. Modern browsers allow us to process everything directly on your device, which means we never upload, transfer, or share your files.

Your files stay completely private. All comparisons happen locally in your browser. Your data stays your business.

LeitmotifChristopher Atlan
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The team behind the tool

We're Leitmotif, a small company from the Alps — Carinthia, Austria and Bavaria, Germany. File comparison is what we do all day: we make Kaleidoscope, the Mac diff app, and diff.tools brings that experience to the browser.

We believe professional tools should be beautiful to look at and fun to use, while giving you all the power you need to get the job done. And we respect your files too much to ever upload them — everything here runs on your machine.

Feedback

We're constantly improving our free online PDF comparison tool to make comparing PDF files faster and more accurate. Share your feedback and help us understand what kind of PDF files you compare.

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