Question 1

Does this show exactly what changed between two versions of a document?

Accepted Answer

Yes -- it's built specifically to surface the real differences between two versions, which matters most for exactly the kind of document (a contract, a financial statement) where an unnoticed change has real consequences.

Question 2

Does this compare the visual appearance of the pages, or just the text?

Accepted Answer

Just the text -- this compares the real, underlying text content of both PDFs, not a pixel-level visual rendering. A purely visual difference (a font change, a color change, an image shifted slightly) with no actual text change behind it won't be flagged. If visual layout differences matter as much as wording, that's not what this catches.

Question 3

Can I view the differences side by side instead of one interleaved list?

Accepted Answer

Yes -- switch to Side by Side view to see the original and revised text in separate columns, with changed lines aligned next to each other, rather than a single unified list with + and - markers.

Question 4

Will this work on scanned PDFs?

Accepted Answer

Only if they already have a real text layer -- a pure scan with no selectable text has nothing for this tool to compare. Run it through OCR PDF first to add a real, searchable text layer, then compare the OCR'd versions.

Question 5

What's the difference between this and Redact PDF?

Accepted Answer

Compare shows you what changed between two versions -- it doesn't modify either file. Redact permanently removes sensitive content from a single PDF. A common real sequence: compare two versions to spot something that shouldn't be shared, then redact it from the file before sending.

Question 6

Can I download a report of the differences?

Accepted Answer

Yes -- Download Report saves a plain text file with every added and removed line marked, so you have a record of the comparison outside the browser tab.

Question 7

Are my files uploaded to a server?

Accepted Answer

No -- comparison runs entirely in your browser, using the same diff engine as the Diff Checker tool. Neither PDF ever leaves your device.

Question 8

Is there a limit to how large a document this can compare?

Accepted Answer

Yes -- if either PDF has more than a few thousand lines of text, comparison is skipped rather than risking your browser becoming unresponsive on a very large document. For a document that size, comparing smaller sections separately is a reasonable workaround.

Compare PDF

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Frequently asked questions