Compare PDF
Compare two PDF files side by side to find differences.
What is Compare PDF Files?
Compare two PDFs page by page and report differences in page count, dimensions, rotation, and file size. Free, private, and processed entirely in your browser.
When should you use it?
This tool is useful when you need to encrypt, unlock, sign, compare, or cover sensitive areas of a PDF.
How Compare PDF Files handles your file
Page geometry is read with pdf-lib in your browser and compared in memory. Nothing is uploaded.
Your device's own CPU does the work, so there is no upload wait and no server-side copy of your document to retain.
Good to know before you convert
- This is a structural comparison, not a text diff. It compares page count, page dimensions, rotation, and file size.
- It will not detect that a word changed on page 4 if the page geometry is identical.
- A .txt report can be downloaded; there is no visual side-by-side page overlay.
How to use Compare PDF Files
Upload your original PDF (Version A) and modified PDF (Version B).
Click 'Compare PDFs' to read and compare the page geometry of both files.
Review the structural differences and download the text report.
Why choose PdfPix for Compare PDF Files?
Private by design
The file is never uploaded. Everything happens inside your browser tab, so there is no remote copy of your document to leak, retain, or subpoena.
No File Size Limits
Because conversions run locally using your computer's CPU power, we don't impose any artificial file size caps, queue delays, or wait times.
100% Free Forever
Get full access to all features without subscriptions, credit card inputs, or registration walls. No branding watermarks added to your outputs.
Universal Compatibility
PdfPix runs smoothly inside any modern browser on macOS, Windows, Linux, iOS, or Android, without needing external applications or plugins.
How PdfPixCompares to iLovePDF & Smallpdf
Unlike traditional cloud PDF services that upload your confidential documents to remote servers, PdfPix processes your files 100% in your browser. No file size paywalls, no task queues, and zero remote data retention.
Frequently Asked Questions
How does the PDF comparison work?
PdfPix reads each file's page tree and compares structural properties: how many pages each document has, the average and per-page dimensions in points, the rotation of each page, and the overall file size. It reports mismatches in a written summary and flags any page that is missing from one of the documents. It does not compare text or pixels, so two documents with identical page geometry but different wording will be reported as matching.
Will it tell me which words changed?
No. Text-level diffing is not part of this tool. If you need to find editorial changes, extract the text from both documents and compare it in a diff tool, or use a word processor's document comparison feature.
Is my business data safe?
Yes. The comparison runs locally on your own machine and neither document is transmitted.
What formats can be compared?
Two or more standard PDF documents. For meaningful results, compare files derived from the same source — comparing a scanned document against a digital original will always report geometry differences.
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