CryptPad

CryptPad is an open-source collaboration suite with end-to-end encryption. Documents are synchronized between collaborators in real time, and because user data is encrypted, an attacker who breaches the server cannot read the stored content. Administrators who run unmodified code and the service itself also cannot see what users store.

The encryption happens in the browser before data is sent to the server or to collaborators. The README is candid about a limit of this model: the code that does the encrypting is delivered by the host server, as on any website, so users must trust the administrator to keep the server secure. Repository topics mention collaborative editing, real-time work and the ChainPad algorithm.

CryptPad is written in JavaScript and licensed under AGPL-3.0. A developer guide covers setting up a local instance, and an admin guide covers production deployments. Official Docker images for AMD64 and ARM64 are published with every release, and a Dockerfile and docker-compose.yml are included in the repository.