Lumo AI by Proton
Lumo is Proton's privacy-first AI chat assistant. It answers questions, searches the web, analyses files and makes images while storing chats with zero-access encryption and no training on your data.
What is Lumo AI by Proton?
Lumo is a privacy-focused AI chat assistant made by Proton, the European company behind Proton Mail and Proton VPN. It works much like other AI assistants, answering questions, writing, analysing files and generating images, but it is designed so that chats are stored with zero-access encryption that Proton itself cannot read.
Proton says Lumo keeps no logs of conversations, never uses them to train models, does not run on an advertising business model and publishes its code as open source. It is aimed at individuals and businesses who want AI help with sensitive topics such as health, finances, contracts or confidential work data.
Key Features of Lumo AI by Proton
Zero-access encrypted history
Saved chats are encrypted so only the account holder can read them. Lumo can also be used in guest mode without an account, including over Tor.
Web search
Built-in web search lets Lumo answer questions about current events while keeping the query away from ad targeting.
File analysis and Proton Drive
Users can upload documents for summaries and analysis, and link files or folders from Proton Drive to give Lumo more context on a project.
Image generation
Lumo can create and refine images from text descriptions, with Proton stating that your images are not reused to inspire other users' results.
Projects and Custom Lumos
Projects group related chats and files, and Custom Lumos let users set up tailored assistants for recurring tasks. Free accounts get one project, while Plus removes the cap.
Lumo AI by Proton Pricing
Lumo has a free tier and a single paid personal plan, with separate options for businesses. Prices can be displayed in USD, EUR or CHF.
Prices checked on October 27, 2026; check the official pricing page for current plans.
The yearly Plus plan was shown with a 23% saving over monthly billing. Plans can be upgraded, downgraded or cancelled at any time with no cancellation fees. Check the official Lumo pricing page for regional prices and business plans.
Who Should Use Lumo AI by Proton?
- People who want AI help but are uncomfortable with chats being logged or used for training.
- Existing Proton users who want an assistant connected to Proton Drive.
- Professionals handling confidential documents such as contracts or client data.
- Users in Europe who prefer a service operating under European privacy law.
- Businesses wanting a confidential assistant alongside Proton's email and storage suite.
Is Lumo AI by Proton Worth It?
Lumo's selling point is trust rather than raw capability. If privacy is the main reason you have avoided AI chat tools, its encryption, no-logs policy, open-source code and European base make it one of the more credible options, and Lumo Plus is priced below many mainstream assistants.
The free plan has fairly tight limits on messages, history and image generation, and Proton does not market Lumo on leading benchmark performance, so users needing the most advanced coding or reasoning features may still prefer other tools. For everyday questions, writing and document work with sensitive data, it is a sensible choice. Visit the official Lumo website to start chatting.