Frequently Asked Questions
Is this PDF compressor really free?
Yes, completely free. No sign-up, no hidden fees, no watermarks, no file size limits. Use it as many times as you need.
Do you upload my PDF to a server?
No. All processing happens locally in your browser using JavaScript and the open-source pdf-lib library. Your PDF never leaves your device. We never see, store, or have access to your files. You could disconnect from the internet and the tool would still work.
How much will my PDF file size be reduced?
Results vary depending on the PDF content. PDFs with unused objects, duplicate resources, or metadata bloat typically see 5-30% size reduction. The tool re-serializes the PDF to strip dead objects and optimize the internal structure. Highly optimized PDFs may see smaller improvements.
Does compression affect the quality of my PDF?
The compression works by re-serializing the PDF structure and removing unused internal objects. Text, vector graphics, and formatting are preserved exactly as the original. The visual quality of your document remains unchanged.
What if my PDF doesn't get smaller?
Some PDFs are already well-optimized and don't have much room for compression. In these cases you may see little to no size reduction. The tool will still show you the before and after comparison so you know exactly what happened.