How to use this PDF tool
- Select original and compressed pdfs.
- Choose the processing option that fits your task.
- Select “Compare PDFs” and wait for the progress bar.
- Review the statistics, then download the newly generated result.
Home › PDF Compression & Optimization › Compare Original and Compressed PDF
Compare Original and Compressed PDF
Check whether a compressed PDF is smaller without obvious page loss or major rendered changes. Select the original first and compressed copy second.
PDF Tool Original and compressed PDFs
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What this tool does
Compare two PDFs by file size, page count, dimensions, and rendered page fingerprints, then export a local JSON compression QA report.
The tool compares bytes, page counts and page sizes, then renders selected pages to small canvases and measures average pixel differences.
The visual score is a screening metric, not a pixel-perfect prepress certification.
Supported formats and limits
| Input | Original and compressed PDFs |
|---|---|
| Output | JSON or CSV report |
| Processing | Local browser session |
| Limits | Available browser memory and canvas size |
Tips for better results
- Keep page count and dimensions identical unless the change is intentional.
- Review pages with the highest difference in a full PDF viewer.
- A larger “compressed” file usually means the chosen settings were ineffective.
FAQ
Does compare original and compressed pdf upload my files?
No. Processing runs in this browser. The page does not send the selected file to a Callpdf server.
Can this tool process a password-protected PDF?
PDFs that require a password are not supported in this version. Remove protection with the correct password before using the tool.
What happens with a very large PDF?
Large documents may use substantial memory and can take longer. Close other heavy tabs and try a smaller file or fewer pages if the browser stops.
Will the output preserve every advanced PDF feature?
The report does not alter the PDF. Its measurements are a practical browser-based inspection and documented limitations still apply.
Which browsers work best for compare original and compressed pdf?
A current desktop version of Chrome, Edge, Firefox, or Safari is recommended. Browser memory limits vary by device.
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Privacy and processing
| Upload | None |
|---|---|
| Storage | Current browser tab only |
| Reset | Revokes generated download URL |