Lumo is Proton’s hosted AI assistant, built by the team behind Proton Mail and Proton VPN. Proton keeps no logs of what you ask or what Lumo replies. Saved conversations are protected by zero-access encryption, meaning Proton itself cannot read them. The client code is open source, and the service operates under Swiss law with full GDPR compliance.
Lumo
proton.me/lumo
Our take
Lumo offers the most credible privacy story among hosted AI assistants: the same Swiss legal framework and zero-access encryption model that Proton has applied to email for years now covers your AI chats. The trade-off is that you are still sending prompts to a server, so the trust requirement does not vanish. It shifts from Big Tech to Proton. The free tier limits usage noticeably; heavy users will need Lumo Plus. Best for people already in the Proton ecosystem who want a private assistant without running local models.
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Lumo alternatives
Duck.ai DuckDuckGo's private AI chat that lets you talk to multiple models with no account and no training on your prompts.
Euria Infomaniak's Swiss-hosted AI assistant that pledges no training on user data and operates under GDPR and Swiss data law.
Apple Intelligence Apple's AI. On-device where it can, with verifiable Private Cloud Compute for the rest.