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PDF Compressor

Optimize PDF structure and compare file sizes. Download a smaller result when object-stream optimization helps.

Document settings

Optimizes document structure without reducing image quality. Already-compressed PDFs may not get smaller.

Files stay on your device. Nothing is uploaded.

Up to 500 pages. Keep originals: editing can invalidate digital signatures.

Output PDFPreview
Your preview will appear here
Output PDF

How pdf compressor works

The PDF is reserialized using compressed object streams. Embedded images are not downsampled.

How to use this tool

  1. Select a supported file from your device.
  2. Adjust the settings and review the updated preview.
  3. Review the output and file details, then download the processed file.

Worked example

A PDF with uncompressed object structure may become smaller; an already optimized scanned PDF may not.

Accuracy and limits

Size reduction is not guaranteed. If output is larger, the tool reports that and recommends keeping the original.

File privacy and supported formats

Files are processed on this device and are not uploaded. File signatures are checked before processing. Use files up to 20 MB each. PDF batches accept up to 20 files and 50 MB in total, with a 500-page output limit. Images are limited to 24 megapixels and 10,000 pixels per side.

Invalid, encrypted or unsupported files produce an error. Keep the original copy, especially for digitally signed documents. Processing is not a malware scan and does not certify a file as safe.

Frequently asked questions

How does pdf compressor work?

The PDF is reserialized using compressed object streams. Embedded images are not downsampled.

What should I check before using the result?

Size reduction is not guaranteed. If output is larger, the tool reports that and recommends keeping the original.

Is PDF Compressor free to use?

Yes. PDF Compressor is free, browser-based, and does not require signup.

Does this tool save my data?

Tool inputs are processed on your device. File tools do not upload your files. Website analytics are described in the privacy policy.

Can I use it on mobile?

Yes. The page is responsive and works on modern mobile, tablet, and desktop browsers.

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Reviewed 2026-10-24. By Mahad and Mehdi Developers.