Proton Lumo Proton, the Swiss company behind Proton Mail and Proton Drive, has launched Lumo, an AI chat assistant that stores all conversations with zero-access encryption, ensuring that not even Proton can read user queries. The open-source tool, which can be used anonymously via Tor, is designed for professionals handling sensitive data and offers a free tier with limited messages and a paid Lumo Plus tier with unlimited chats and higher model usage. Stars Last commit Repository age Version License Repository Lumo is an AI chat assistant built by the team behind Proton Mail and Proton Drive. Its core promise is simple: your conversations stay yours. Every chat is stored with zero-access encryption, meaning not even Proton can read what you've asked. No logs, no ad targeting, no data sold to third parties. Most popular AI chat alternatives /alternatives/t3-chat collect and retain your messages, often using them to train future models or serve targeted ads. Lumo's open-source code lets anyone verify that it doesn't. You can also use it anonymously via Tor without creating an account. Based in Switzerland and subject to GDPR, Lumo sits outside US jurisdiction and Big Tech infrastructure. You can delete your account at any time, and Proton cannot share your data with governments or advertisers even if asked. What Lumo can do day-to-day: The free tier covers limited messages, image generations, and one project. Lumo Plus adds unlimited chats, higher model usage, more image generations, and unlimited projects. It's aimed at professionals and teams who handle sensitive information and can't afford to have that data harvested by the tools they rely on daily. Stars Last commit Repository age Version License Repository Every Sunday we deconstruct one proprietary app and pick the best open source alternatives worth switching to. Stars Last commit License Stars Last commit License Stars Last commit License Stars Last commit License Compare with Stars Stars Stars Stars Stars Stars Stars Stars Stars License Compare with License Compare with Last commit License Compare with Last commit License Compare with License Compare with Last commit License Compare with License Compare with Last commit License Compare with License Compare with License Compare with