Compress PDF Online Free

Results depend on the images and encoding already inside the PDF. Image-heavy files usually offer the largest savings; text-only or previously optimized files may change very little. Extreme mode adds a more aggressive pass.

Recommended mode balances image quality and file size. Extreme mode can visibly soften scanned text, handwriting, stamps, and photographs, so compare the result with the original. Born-digital vector text is not rasterized.

Selected PDF content is processed in browser workers and is not uploaded to BytesPDF servers. Device security, browser extensions, loaded code, downloads, and the eventual recipient still matter.

Desktop browsers accept files up to 150MB. Mobile browsers use a 50MB limit to reduce memory crashes. Device memory and PDF complexity can lower the practical limit.

BytesPDF runs in current browsers with the required Web Worker, WebAssembly, canvas, and memory support. Capability varies by browser and device; no app installation is required.

BytesPDF performs PDF processing locally in the browser with Web Workers and MozJPEG WebAssembly, so document content is not sent to BytesPDF servers. Your browser, device, extensions, and the destination you later choose remain part of your security context.

Yes. BytesPDF uses an adaptive multi-pass WebAssembly pipeline for embedded images. Born-digital vector text is not rasterized, but scanned text is part of an image and can soften at stronger settings.

BytesPDF rejects PDFs containing a cryptographic signature because rewriting any bytes would invalidate it. Keep digitally signed files and required PDF/A archival masters unchanged. For complex PDFs, inspect bookmarks, links, forms, annotations, accessibility, and color after compression.

BytesPDF compression requires a modern browser with WebAssembly, Web Workers, and OffscreenCanvas support. Current Chrome, Firefox, Safari, and Edge releases are recommended; large files may be limited by device memory.