PDF Compression

PDF compression reduces file size by targeting its largest components: embedded images, fonts, and metadata. Image compression is the biggest lever — a PDF with high-resolution photography can shrink by 70-90% by downsampling images to screen resolution. Lossy versus lossless compression is the key tradeoff: lossy achieves smaller files but degrades image quality; lossless shrinks the file less but perfectly preserves content.

Common use cases include email attachment limits (typically 10-25MB), upload restrictions on academic submission portals, and storage optimization for document archives. A 50MB portfolio PDF that needs to go through a university application system is a practical problem that compression solves in seconds.

Where the compression runs matters as much as how well it works. A client-side compressor keeps sensitive documents — tax returns, legal filings, medical records — on the device, while a server-side one requires uploading them to a third party first. Tools that expose a quality level let you control the size-versus-fidelity tradeoff explicitly rather than guessing at a preset.