Frequently Asked Questions
- How does the PDF compressor work?
- The tool uses a professional PDF engine running directly in your browser to recompress images and optimize content streams in your PDF. Nothing is uploaded to any server.
- Which quality preset should I choose?
- Screen is ideal for sharing via email or web — smallest file, lowest quality. eBook is a good balance for on-screen reading. Printer and Prepress are for high-quality print output and produce larger files.
- Why is my compressed file larger than the original?
- Some PDFs are already well-optimized, or consist mainly of vector graphics and text. In those cases, re-encoding can add a small overhead. Try a lower preset for better results.
- Does the tool upload my file?
- No. Everything runs in your browser. Your PDF never leaves your device and is never sent to any server.
- Does compression affect the quality of text and fonts?
- Text and vector elements stay sharp at all quality levels. Only raster images are downsampled. Fonts are kept embedded but subsetting reduces their footprint.
- Is there a file size limit?
- There's no strict limit — it depends on your device's available memory. Very large PDFs (over 100 MB) may be slow to process or may fail on low-memory devices.
- Is the PDF Compressor free?
- Yes, completely free. No account, no sign-up, no limits.
