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.
Reviewed by Marcus Holmberg
Lumo
proton.me/lumo 2 ratings so far*
Rate Lumo: No account needed
Threat level
Covered
A covered pick. Anyone can use it as a private drop-in, with no setup or know-how. Enough for most people. Threat levels
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.
Website at a glance
proton.me
B+ score 80
Solid website security headers
Graded by Mozilla HTTP Observatory, tested 1d ago
Inspect this site yourself
Measures the security configuration of the tool's own website, not the privacy of the product itself. A strong tool can still score low here.
Lumo alternatives
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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.
Skales Skales is a local AI desktop agent that runs on your computer with any AI provider you choose. All conversations and data stay on your machine, and you control which model and which API keys you use.
Ollama Ollama lets you download and run large language models locally via a simple CLI and REST API. Supports a growing library of open models including Llama, Mistral, and Gemma on Windows, Mac, and Linux with no data sent to the cloud.
llamafile A Mozilla project that packages a complete LLM and its runtime into a single executable file. Download one file, run it on Windows, Mac, or Linux with no installation, no dependencies, and no network connection required.
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