Reduce your PDF files by up to 90% without losing visible quality. Perfect for email, web uploads, and storage. 100% private — files never leave your device.
Powerful features, completely free — no strings attached.
Three simple steps — no software, no waiting.
PDF compression reduces the file size of a PDF document by re-encoding its internal streams, removing redundant data, and optimizing the internal cross-reference structure. A compressed PDF contains the same visual content but takes up significantly less storage space — making it faster to email, share, and upload.
Compressfy's online PDF compressor uses the pdf-lib JavaScript library to process your document entirely within your browser. That means your files are never transmitted to any server — making this one of the most privacy-safe PDF compression tools available. There is no file size limit, no signup, and no hidden costs.
PDFs become large when they contain high-resolution images, embedded fonts for every glyph, unoptimized content streams, or when created by certain software that adds verbose internal structures. A scan at 600 DPI produces a massive PDF — often 10–50x larger than necessary for screen viewing or emailing.
Screen (72 DPI) is ideal for documents viewed only on screen — smallest file size, slight quality reduction for high-res images. eBook (150 DPI) is the balanced default — good quality for both screen and light printing. Printer (300 DPI) maintains professional print quality while still reducing file size compared to the original.