The PDF Toolbox blog

This blog covers three things: practical PDF workflows (how to merge, compress, redact, and convert documents without wasting time), the internals of the PDF format (why files balloon in size, what metadata they carry, how compression actually works), and document privacy (what happens to your files when you upload them to online converters, and how to avoid that entirely). Every article is written by the people who build the tools on this site, all of which process files locally in your browser.

Why local, in-browser PDF tools are safer than upload-based converters

When you upload a contract or a medical record to a free online converter, that file travels to someone else's server, gets processed there, and may sit in storage for hours or days under a privacy policy you never read. This post walks through what actually happens to an uploaded file, which document types should never leave your machine, and how to verify with your browser's DevTools that a local tool really keeps files local.

How to actually reduce PDF file size (and what makes PDFs huge)

Most oversized PDFs are dominated by one of a small number of things: high-resolution scanned page images, embedded font programs, or duplicated resources. This post explains which one is inflating your file, why different "compress PDF" tools produce wildly different results, and gives realistic size expectations for each document type — plus the cases where you should not compress at all.