Lumo is Proton’s answer to privacy-hostile AI chat: conversations are not logged or used for model training, history is encrypted with zero-access design, and the whole thing comes from the Swiss company behind Proton Mail. For legal, medical or simply private questions, it offers the same assistant convenience without feeding an advertising profile.
The free plan covers limited weekly usage with no card required; Lumo Plus costs $12.99 per month ($9.99 per month billed annually at $119.88) and unlocks more models, higher limits and file uploads. If you already trust Proton for mail or VPN, Lumo Plus slots into the same privacy stack – a differentiated position ChatGPT and Gemini deliberately do not occupy.