Editorial assessment
Based on accepted keyword evidence and public product materials checked on 2026-08-17, Lumo is listed under General Assistants. This editorial classification is not an endorsement; verify exact features, limits and availability on the official website.
What it helps you do
Evaluate Lumo for General Assistants workflows.
Compare its documented capabilities with other products in General Assistants.
- Features, quotas, pricing and regional availability may change; confirm current terms on the official website.
- Review important outputs and data-handling terms before relying on the product for sensitive work.
Frequently asked questions
Billing and subscription answers verified against the official source.
Is Lumo free to use?
Yes, Lumo is free to use and you can start chatting without even creating a Proton account. Lumo's free plan includes essential features that support your productivity, like basic chat history, web search, and the ability to upload individual small files — all while keeping your conversations private with zero-access encryption.
What's the difference between Lumo's Free and Plus plans?
Lumo's Free plan offers essential features, but it comes with usage limitations on chats, favorites, uploads, images, and projects. Upgrading to Lumo Plus gives you more flexibility and advanced features while maintaining the same privacy guarantees. Upgrade to Plus to unlock unlimited chats, extended chat history, unlimited favorites and projects, plus the ability to upload multiple large files.
Does Lumo have usage limits?
Yes. Lumo's free plan has a limited number of Max model usage, messages, chat history, image generations, Projects, and Custom Lumos. Lumo's paid plans Plus and Lumo for Business have much higher usage limits.
Are business plans available for Lumo?
Yes, Lumo for Business offers confidential AI for teams. It is available through Lumo Professional or as part of Proton Workspace, a privacy-first suite of solutions including email, calendar, cloud storage, VPN, password manager, and video conferencing. Lumo for Business is great for tasks like drafting contracts, analyzing data, and brainstorming ideas while maintaining company and client confidentiality.
What happens to my chat history if I upgrade to Lumo Plus?
Your data stays yours and your chat history carries over seamlessly. Any conversations you've used with the Free version of Lumo will remain accessible and encrypted with zero-access encryption. The main difference is that with Plus, you'll gain extended history retention and the ability to save unlimited favorites and projects going forward.
Can I change my plan or cancel at any time?
Yes, you can upgrade, downgrade, or cancel your Lumo subscription at any time. If you downgrade from Plus to Free, you'll retain access to your saved chats, but you'll lose Plus features like unlimited chats and extended history once your current billing period ends. There are no long-term commitments or cancellation fees, so you're always in control of your subscription.