Lumo by Proton

Lumo by Proton is a privacy-focused AI chat assistant. Think of it as a ChatGPT alternative where your conversations are encrypted end-to-end with zero-access encryption — meaning even the company behind it can't read them. You can ask it questions, brainstorm ideas, generate images, and organize projects, all without worrying that your data will be harvested for ads or AI training.

How does it work? Lumo stores every chat with zero-access encryption, so only you hold the keys. The code is fully open source, so anyone can audit it. Proton is based in Switzerland and complies with GDPR, giving you strong legal protections. The free tier gives you limited access to the "Max" model, limited messages, and one project. Upgrade to Lumo Plus (€9.99/month billed yearly) for unlimited chats, more image generations, and unlimited custom Lumos (custom AI agents). The comparison table on the site shows Lumo is the only major AI assistant that doesn't use your data to train AI, doesn't log chats, and can't share data with third parties.

Who should use Lumo? Anyone who values privacy — journalists, lawyers, doctors, or just someone who doesn't want their personal questions sold to advertisers. It's also a solid choice for businesses that need to discuss confidential information without exposing it to third-party AI services. If you're already in the Proton ecosystem (Mail, VPN, Drive), Lumo fits right in.