Proton, the company known for its encrypted Proton email service and Proton Pass password manager, has introduced a new AI assistant called Lumo, designed to prioritize user privacy.
The Lumo AI chatbot can generate code, summarize documents, write emails, and more—all while keeping data stored locally on users’ devices.
Unlike many AI tools from major tech firms, Proton says Lumo employs “zero-access” encryption, meaning only users hold the key to decrypt their data. This prevents Proton or any third parties, including advertisers and governments, from accessing personal information. The company also emphasized that Lumo won’t use customer data to train its AI models.
By default, Lumo does not search the web, a feature Proton disabled to maximize privacy. Users who enable web searches will have queries routed through “privacy-friendly” search engines. The chatbot can also read and analyze uploaded files, including those from Proton Drive, without retaining any data.
Proton positions Lumo as a secure alternative to AI assistants like ChatGPT, Meta AI, Gemini, and Microsoft Copilot.
Lumo runs on multiple open-source models, including Mistral’s Nemo and Nvidia’s OpenHands 32B, selecting the best one for each task. For example, coding-related questions are handled by OpenHands, which specializes in programming.
The Proton Lumo AI chatbot is available now at lumo.proton.me or via iOS and Android apps. Free users get limited weekly queries and encrypted chat history, while a $12.99 monthly “Lumo Plus” plan offers unlimited chats and larger file uploads.