Lumo is an encrypted version of artificial intelligence. I came across it through Proton Mail, a Swiss technology company owned by Proton AG.
The Proton Foundation, a non-profit organisation, has been the majority shareholder of Proton AG since June 2024. This change was designed to ensure Proton remains focused on privacy rather than profit
Some remaining shares are held by Proton employees, a Swiss nonprofit foundation (FONGIT), and a small portion by users
An AI assistant should empower you, not exploit you for your data. That’s why we built Lumo: To bring you all the benefits of AI, without compromising your privacy and data security.
AIs from Big Tech are built on harvesting your data. But Lumo is different. It was created by the scientists behind innovative, privacy-first services like Proton Mail and Proton VPN. And it’s owned by a Swiss nonprofit, whose mission is to advance privacy and never make money from user data.
We keep no logs of what you ask, or what Lumo replies. Your chats can’t be seen, shared, or used to profile you. Lumo saves nothing on our servers.
Thanks to zero-access encryption, your saved conversations can only be decoded and read on >your device. Neither Proton nor anyone else can see them.
Lumo’s code is fully open source, so anyone can independently verify that it’s private and secure—and that we never use your data to train the model.
Your data isn’t shared with advertisers, governments, or anyone else. Lumo is a European service subject to GDPR, so you can delete your data anytime.
Lumo provides a similar response to ChatGPT when given the same prompt.
I asked both Lumo and ChatGPT the same question about software for a device I had just bought. Initially, ChatGPT gave a more detailed response, but Lumo gave a similar response when I toggled ‘Web Search’. 'Web Search' is now the default setting.
Lumo AI was designed to be fully encrypted, and this works very well.
Because Lumo doesn't keep information about your interests, it doesn’t tailor future responses to match your needs. ChatGPT asks your permission before doing this.
ChatGPT provides citations for its sources. Lumo provides citations when ‘Web Search’ has been activated.
I wanted a cover image for this article, so I asked Lumo to generate a 16:9 image of Lumo AI. This is the response that I got:
“I can’t create images directly, but you can easily generate a 16 : 9 ratio illustration of Lumo AI using a graphic‑design or AI‑image tool.”
Instead, Lumo provided me with a prompt, which I admit was better than my attempt.
Create a sleek 16:9 illustration of Lumo AI, a privacy‑first virtual assistant. Use Proton’s blue‑teal color scheme, incorporate a glowing light‑burst logo, subtle shield shapes, and modern chat bubble icons. Clean, minimalist style with a subtle gradient background.
I then used this prompt with ChatGPT, which generated the cover image for this post.
Lumo has recently introduced image generation, and using the same prompt, I got this result:
Projects are a recent addition to Lumo. They are encrypted workspaces that are organised containers for specific tasks or workflows. You can include chats, files, and custom instructions for any particular project.
Their key characteristics are:
Common Uses:
When Ghost Mode is activated in the sidebar, conversations are deleted upon completion.
The sidebar is revealed by clicking the sidebar icon in the top left corner of the window.
The free version has recently become too restrictive, with chat history limited to the previous seven days. This limited search history is shown in the sidebar.
One way around this is to search for your hidden chats.
Opening the sidebar reveals this notification near the bottom:
I clicked the ‘Upgrade’ button, and after dismissing a 'pop-up ', these options appeared:
No mention of Lumo Plus!
So, I clicked ‘Explore other Proton plans’. This time, the page provided information about the Lumo Plus plan:
Price
9.99 € per month - the same price as Proton Unlimited.
Unlimited daily chats
Web search access
Full chat history with search
Unlimited favourites for quick access
Upload and query multiple large files
Access to advanced AI models
The Lumo Plus plan also includes selected benefits from:
I won’t go into these additional benefits here because this article is about Lumo AI.
Like other Proton products, the subscription plan is far too complicated. If you want to explore the Proton plans, you can go to https://proton.me/pricing where each product has its own tab.