Compress PDF Online
Reduce your PDF file size instantly. Choose High Quality, Balanced, or Maximum compression – no watermark, no sign-up, your file never leaves your browser.
- Is it free to compress a PDF?
- Yes, completely free. No sign-up, no subscription, no watermark - ever. You can compress as many PDFs as you want at no cost.
- How do I compress a PDF without losing quality?
- Choose 'High Quality' mode. It reduces file size while keeping images sharp and text readable. Use 'Maximum' compression only when file size matters more than image crispness.
- Does it add a watermark to my PDF?
- Never. CompressPDF does not add any watermark, logo, or branding to your compressed PDF output.
- Is there a file size limit?
- There is no server-side limit because everything runs locally in your browser. The practical limit depends on your device memory - most modern devices handle files up to several hundred MB easily.
- Is my PDF uploaded to a server?
- No. All compression happens locally in your browser using JavaScript. Your file never leaves your device and is never sent to any server.
- Can I compress a PDF on iPhone or Android?
- Yes. The tool works on all modern mobile browsers including Safari on iOS and Chrome on Android.
- How much can I reduce a PDF file size?
- Typical reductions are 40-80% depending on the original content. PDFs with many high-resolution images compress the most. Text-only PDFs may compress less.