Compare Two PDFs and See What Changed
To compare two PDFs, upload both files and view them side by side with synchronised scrolling to spot revisions page by page. Both documents are rendered entirely in your browser, so neither is uploaded. The side-by-side view works best on a tablet or desktop screen.
Compare two PDF documents side-by-side in a clean workspace.
Drop two PDF files here, or click below to upload both.
Runs in your browser · file never uploaded
This tool runs entirely in your browser using WebAssembly. Your file is never uploaded — it stays on your device from start to finish.
Full detail in our privacy policy.
At a glance
0 KB
Uploaded to any server
2 files
Side-by-side review
Fast
Visual comparison setup
Start in 3 easy steps
A quick visual tour of the private PurePDF workflow.
Upload two PDFs
Choose the original and modified files together.
Open comparison
Load both previews into the workspace.
Review changes
Read the highlighted text diff, then download the report.
Built for everyday PDF work
Fast, clear, and built around local browser processing.
Side-by-side view
Load two documents and compare pages visually.
Private review
Documents stay in your browser session.
Word-level diff
Text differences are highlighted per page and exportable as a PDF report.
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Frequently
Asked
Questions
Quick answers about this PurePDF workflow.
Is the PDF compare tool free?
Yes. Comparing two PDFs side by side is completely free.
Do my files get uploaded to a server?
No. Both documents are rendered and compared entirely in your browser.
How does PDF comparison work?
Upload the original and the revised PDF. The text of each page is compared word by word, added and removed words are highlighted, and you can download the result as a comparison report PDF.
Can I compare different versions of a contract?
Yes. The word-level comparison shows every wording change between two drafts, page by page, so edits cannot slip through unnoticed.
Is there a file size limit?
No limit set by us — both documents are rendered on your device, so available memory is the practical ceiling.
Can I compare PDFs on mobile?
Yes, though the side-by-side view works best on a tablet or desktop screen.
How to compare two PDF files and see exactly what changed
Why comparing by eye does not work
When a contract, policy, or manuscript comes back with revisions, the changes that matter are often a single word: “may” became “shall”, a date moved, a figure gained a zero. Reading two long documents side by side and hoping to notice is slow and unreliable, and tracked changes are often missing once a file has been exported to PDF.
Compare PDF does the checking for you. It compares the text of both documents page by page and highlights every word that was added or removed.
How the comparison works
Upload the original and the revised PDF. PurePDF extracts the text of each page and compares the two word by word. Added words and removed words are highlighted in the result, and a summary shows how many words changed and on how many pages, so you can go straight to the pages that differ.
When you are done, download the comparison as a PDF report to attach to an email, a ticket, or a review record.
Good uses for a PDF comparison
- Checking a counterparty’s edits to a contract before signing.
- Reviewing a new version of a policy, handbook, or terms of service.
- Confirming that a typesetter or designer did not introduce errors into a manuscript.
- Auditing what changed between two releases of a specification or manual.
Limits worth knowing
The comparison works on the text layer. Changes to images, colors, or layout that do not change the words will not appear in the diff, so glance over the side-by-side preview for visual changes. Scanned PDFs have no text layer; run them through OCR PDF or Scan to PDF first so there is text to compare.
Both files stay on your device
Contracts and drafts are sensitive. Both documents are rendered and compared entirely in your browser, and neither is uploaded to a server. There is no size limit set by us; your device’s available memory is the practical ceiling.
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