How KuroPDF works
Every one of our 30 tools runs entirely inside your browser. Your files are never uploaded, streamed, or stored on a server - there is no server.
Nothing leaves your device
Files are read locally with the File API and processed in memory. Open your browser's network tab and you'll see zero uploads.
Powered by WebAssembly
We use pdf-lib, pdf.js and a WebAssembly build of qpdf for real AES encryption, all client-side.
Fast and multi-threaded
Heavy work runs in a pool of Web Workers across your CPU cores, so the interface stays responsive on big documents.
Works offline
Install KuroPDF as an app. After the first visit it works with no internet connection at all.
Why local matters
Cloud converters upload your documents to someone else's computer, often with file-size caps and retention policies. For bank statements, contracts, medical records or legal discovery, that's a real risk. KuroPDF removes it entirely: no upload means no breach, no limits, and no waiting on a network round-trip.