Lumo

Lumo is Proton's AI assistant for chat, research and everyday work. Proton launched the service in July 2025. It is operated by Proton AG in Switzerland and is available on the web and in mobile apps. People can use it to ask questions, draft text, summarize documents and explore ideas.

Help with writing and information

Lumo can revise or translate text, explain topics, assist with code and summarize uploaded files. The assistant is designed for both everyday questions and work involving longer documents, so users can ask follow-up questions about material they provide.

Optional web search and images

When a prompt needs recent information, users can enable web search. Lumo can also generate images from descriptions and help organize tasks into plans. These functions extend its use beyond a basic question-and-answer chat.

Private chat history

Proton says Lumo does not keep logs of conversations or use them to train its models. Saved chat history is protected with zero-access encryption, so Proton cannot read it. Ghost Mode lets users discard a chat when the session closes.

Models and infrastructure

Proton says Lumo uses open-source language models running on servers it controls in Europe. The company publishes Lumo's code and describes the service as part of its broader privacy ecosystem, alongside tools such as Proton Mail and Proton VPN.

For personal and work use

The assistant can help with emails, study, research, planning and document review. Guests can start a chat without a Proton account, while signing in provides access to encrypted chat history and additional account features.