What it is
Lumo is Proton's general chat assistant, from the company behind Proton Mail and Proton VPN. It answers questions, drafts and summarises text, searches the web with cited sources, analyses uploaded files and images, and generates or edits images. Saved chats use zero-access encryption, so Proton says it cannot read them, and Proton states it keeps no logs and does not train on your conversations.
Who it suits
People and small teams who handle sensitive material, such as contracts, legal files or client data, and want a mainstream-style assistant with stronger privacy terms. It fits best if you already use Proton Drive, since you can link files and folders from it. You can try it without an account, including over Tor.
Pricing
The free plan limits messages, chat history, image generations and use of the stronger Max model, and allows one Project. Lumo Plus raises those limits and adds unlimited Projects and custom assistants. Proton's own site prices Plus in euros, dollars or Swiss francs; in the UK App Store it is £10.90 a month or £99.99 a year. A Lumo Professional plan covers business teams.
Where it falls short
There is no desktop app or browser extension yet, and voice input is on mobile only. Proton names its models (Lumo 2.0 Lite and Max, plus Apertus 1.5) but not the underlying base models. A developer API is on Proton's 2026 roadmap rather than available now.
