Lumo (Proton)

About Lumo (Proton)

Lumo is Proton AG's AI assistant, launched in July 2025 as a privacy-focused alternative to ChatGPT, Gemini, and other mainstream AI chatbots. Built by the same team that created ProtonMail, ProtonVPN, and Proton Drive, Lumo applies Proton's signature approach to privacy—zero-access encryption, open-source code, and Swiss legal jurisdiction—to the AI assistant category. Lumo's architecture is designed so that Proton cannot read user conversations. Chats are encrypted on-device before being sent to Proton's infrastructure, and the company uses zero-access encryption so that even Proton engineers cannot access conversation content. The AI runs on open-source models including Mistral and others, with Proton operating its own inference infrastructure in Germany and Norway. Proton AG is incorporated in Switzerland, which provides one of the strongest privacy jurisdictions globally. Switzerland is not in the EU but has GDPR adequacy, its own Federal Act on Data Protection (FADP), and critically, is outside the reach of both the US CLOUD Act and EU data retention directives. This makes Swiss jurisdiction particularly attractive for privacy-sensitive AI applications. Lumo's code is fully open-source, allowing independent security audits. Proton AG holds ISO 27001 and SOC 2 certifications at the organisational level. The combination of Swiss jurisdiction, zero-access encryption, open-source transparency, and Proton's established privacy track record makes Lumo one of the strongest privacy-first AI assistants available. Pricing includes a free tier with limited usage (no account required) and Lumo Plus at $12.99/month for unlimited access.