Yes. Sync is opt-in and off by default: you turn it on per group of documents, and nothing is uploaded until you do. Your encryption key is managed for you, so there is no passphrase to remember and a forgotten password can be reset without losing what you synced. Documents travel and rest as ciphertext, but the server holds the key, so sync is not end-to-end encrypted. A few accounts created before 26 October 2026 hold their own key instead; Settings tells you which mode you are in.