Building an Open-Source, Zero-Knowledge DocSend Alternative with React 19 and Supabase
Why We Built DocTransfer Sharing sensitive documents like pitch decks, financial reports, or legal contracts shouldn't require paying $250+/month for platforms that store your unencrypted files on their servers. We built DocTransfer (and open-sourced it on GitHub ) as a privacy-first, client-side encrypted document sharing and Virtual Data Room (VDR) platform. Zero-Knowledge Cryptography…
DocTransfer is an open-source, zero-knowledge document sharing platform that aims to provide privacy-first document sharing and Virtual Data Room services. The developers created it to avoid paying high monthly fees for platforms that store unencrypted files on their servers. DocTransfer implements zero-knowledge cryptography architecture, ensuring that encryption happens entirely on the client-side before any data leaves the browser.
The client-side encryption utilizes WebCrypto API and OpenPGP.js for OpenPGP encryption, as well as AES-256-GCM for AES encryption. Encryption keys are kept in URL hash fragments (#key=...) and never sent to the servers. Digital Certificate generation is also part of the security measures, along with biometric sign-in using SimpleWebAuthn.
The frontend of DocTransfer is built with React 19, TypeScript, Vite, and Framer Motion. The database and authentication system are powered by Supabase, which includes PostgreSQL with strict Row-Level Security, Edge Functions, and Storage. Document processing is handled by pdf-lib, react-pdf, and pdfjs-dist libraries.
Users can interact with the platform through a live app available at doctransfer.app. The developers encourage feedback on the client-side encryption flow, PDF rendering optimizations, and overall user experience, and welcome contributions from the open-source community.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
