Proton Lumo — a privacy-first chatbot built on open-source models

Proton launched Lumo, a privacy-focused chatbot built from open-source models. Lumo encrypts conversations, avoids using user data to train models, and integrates with Proton’s ecosystem (Mail, Drive). Proton positions Lumo as a practical, lower-cost alternative to bigger, data-driven assistants.

Key points

• Privacy-first: end-to-end encrypted chats and a no-logs stance; features like Ghost Mode to discard conversations.
• Open-source models: Lumo stitches together smaller open models (Nemo, OpenHands 32B, OLMO 2 32B, Mistral Small 3) to be resource-efficient and nimble.
• Pricing: free tier available; paid Plus tier removes limits for $13/month (cheaper than many rivals).
• Philosophy: Proton argues many users don’t need the largest models — a smaller, well-integrated model can be sufficient for everyday productivity.
• Targets users who value privacy over flashy features and ads.

Why it matters

Big AI platforms may monetize via ads or data. Proton aims to offer a sustainable, privacy-preserving alternative without venture-capital pressure to sell user data. While it won’t replace giants overnight, Proton’s existing user base (100M Proton Mail users as of 2023) gives it a footing to grow.

Try it

Start chatting at https://lumo.proton.me or read Proton’s announcement at https://proton.me/blog/lumo-ai.

Would a privacy-first assistant be enough for your daily workflows? Share your thoughts in the comments below.