How to Compare Two PDFs and Spot Differences
Comparing two versions of a PDF is essential when reviewing contracts, revised reports or design proofs — you need to see exactly what changed between drafts. SwiftPDFLab’s Compare PDFs tool lines two documents up and highlights the differences, and the whole comparison runs client-side in your browser, so confidential documents are never uploaded to a server.
Step 1: Open the Compare Tool
Go to the Compare PDFs tool. You can also open two documents in the SwiftPDFLab Editor and run a comparison from there.
Step 2: Upload the Original and the Revision
Load the older document as the original and the newer one as the revised version. Order matters: the tool reports what changed going from the first file to the second.
Step 3: Run the Comparison
Start the compare. The tool analyses both documents and marks up differences — typically added content, removed content and changed text — so you can review them page by page.
Step 4: Review and Export
Work through the highlighted differences. When you are satisfied, download the comparison result to keep a record or share the redline with collaborators.
Pro Tip
Comparison works best when both files have the same page order and orientation. If one draft has inserted or reordered pages, align them first with the Merge/Split or Organize tools so genuine content changes stand out from layout shifts.
Spot Every Change — Free & Private
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Open Compare Tool