CryptPad is a collaborative office suite that is end-to-end encrypted and open-source. You can create simple office documents and collaborate with others via the browser. The data is stored end-to-end encrypted. Means: even the server can’t read/decrypt your documents. Only you and the people you share the content with are able to read/write the data. The encryption keys are never transmitted to the server.

URL: https://cryptpad.mxhdr.net