What WebAssembly actually buys you here
WebAssembly (WASM) lets code originally written in a systems language like C++ or Rust run inside the browser at near-native speed — orders of magnitude faster than the equivalent logic written in JavaScript. That's what makes browser-local PDF processing practical instead of painfully slow.
PrivaPDF compiles its PDF engine to WASM, so operations like compression, merging, and format conversion run on your device's CPU at speeds comparable to a native desktop app, without needing to install one — the browser tab is the whole application.