Why you'd need to convert PDFs with no internet
There are more situations than you'd expect where connectivity isn't available: mid-flight, in hospitals and clinics with strict network controls, on air-gapped machines used by government, legal, and financial institutions, in remote field locations, or on corporate networks that block outbound traffic to consumer cloud services by policy.
Upload-based converters like Smallpdf or Adobe Acrobat Online need a live connection because the conversion happens on their servers — your file goes up, gets processed, and a result comes back down. No internet, no conversion. Even tools that look local often phone home for license checks or telemetry; you can confirm this by watching the Network tab in DevTools.
How PrivaPDF keeps working with no connection
PrivaPDF uses a Service Worker to cache the entire application — JavaScript, the WebAssembly binary, CSS, and fonts — to your browser's local storage on first visit, and the Cache API to keep those assets available across sessions. After that first visit, every conversion is self-contained: assets are served from cache, the WebAssembly binary processes your file in memory, and the result downloads directly — with zero network activity at any step. Test it yourself: do one conversion, switch on Airplane Mode, hard-reload the page, and convert again. It works identically.
Installing it as a desktop app
For the smoothest offline experience, install PrivaPDF as a Progressive Web App: open privapdf.net/convert in Chrome or Edge, click the install icon in the address bar (or choose “Install PrivaPDF” from the browser menu), and it appears in your dock or Start Menu like a native app. Firefox doesn't support PWA installation, but still caches the Service Worker so the converter works offline in a regular tab.
Using it on air-gapped machines
Air-gapped machines can't reach privapdf.net directly. Either pre-cache on a connected machine first — visit the site, run one conversion to trigger the Service Worker cache, then transfer that browser profile to the air-gapped machine — or self-host the app, since PrivaPDF is a standard Next.js application that can be built and served inside a closed network.