Compress PDF Files Online Free

Our tool leverages modern WebAssembly and JavaScript engines (Mozilla's PDF.js and PDF-Lib). Your browser reads the PDF binary, optimizes images, recompiles streams, and outputs a compliant compressed PDF directly in memory without transferring data across the Internet.

Select the Extreme Compression preset. For scanned documents or certificates, you can also expand the Advanced Settings and toggle Convert to Black & White / Grayscale. This dramatically reduces color overhead and drops file sizes to under 100KB–200KB while keeping text legible.

Yes! The Smart Balanced mode maintains a high 150 DPI resolution, ensuring that typography, small print, signatures, and stamps remain crisp, clear, and perfectly readable on computer screens and mobile displays.

No. Because the processing occurs locally inside your browser, there are no artificial 20MB or 50MB server limits. You can compress multi-page contracts, full books, and high-resolution brochures without restrictions.