Compare two PDFs
Two versions, one read: what moved jumps out.
Your files never leave your deviceOriginal version
Drop the PDF here
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Modified version
Drop the PDF here
or click to browse your files
How to compare two PDFs, step by step
Comparing two versions of the same document needs no software and no upload: everything is computed on your own device, page by page.
Drop in the two versions
Drag one PDF into the “Original version” column and the other into “Modified version”. Each drop is read right away: a password-protected file is rejected on the spot, before any comparison starts.
Start the comparison
The “Compare” button only turns on once both documents are loaded. VellumPDF extracts the text from both sides, then also compares the visual appearance of each page, with a progress bar.
Read the summary banner
The result states how many pages were changed, added or removed out of the total. Tick “Also show identical pages” if you want to review those too — it is unticked by default. “Export the report” saves these differences in a PDF to attach or file.
Switch between Text and Visual on each page
Every page card has its own toggle between word-for-word and visual comparison, useful for spotting a change in an image or layout that a plain text diff would miss.
The tool only ever handles two documents at a time: to track a series of versions, run it again for each successive pair.
Frequently asked questions
How do I compare two versions of a PDF to see what changed?
Drop in both versions of the document: VellumPDF reports what was added, changed or deleted, with the differences highlighted directly on the pages.
Does the comparison work word by word, or is it purely visual?
Both modes are available: a word-by-word comparison to spot text changes, and a pixel-by-pixel comparison for layout differences.
Does comparing two PDFs upload both files to a server?
No, both documents are processed in your browser, with nothing sent to a server; the tool is free and unlimited.
Why two readings, textual and visual?
Because they answer two different questions. The text comparison runs a word-by-word diff and tells you WHAT changed: an amount, a date, an added clause. The visual comparison works pixel by pixel and shows WHERE it changed, including where there is no text — a replaced logo, a shifted table column, an added signature.
Does the comparison catch a change inside an image or a table?
Yes, through the visual reading. A purely textual diff would see nothing if a logo is replaced or a column moved: those elements contain no words at all. That is exactly where pixel-by-pixel comparison is irreplaceable.
Can I compare two documents with different page counts?
Yes. Pages are set side by side in order, and pages with no counterpart appear as entirely added or entirely removed. That is the expected behaviour when one version slips in an appendix.
Can I keep a record of the differences?
Yes: “Export the report” produces a PDF with the names of both files, the date and the summary, then, for each changed page, the added passages in green and the deleted ones struck through in red, with both pages side by side and the changed areas highlighted. It can be attached to an email or filed with the case.