Conversations Proton cannot read
Your history is saved encrypted: only your account can open it. Proton keeps no logs of your conversations and does not use them to train the AI.
AI tools · Assistants
Lumo pricing, use cases, and first steps
Lumo is an assistant, like ChatGPT, created by Proton, the Swiss company behind Proton Mail. You write a request and it answers: drafting, summarizing, translating, searching the web, reading a file. What sets it apart: your conversations are encrypted, Proton cannot read them, and they are not used to train the AI.
Lumo has a free plan. The recommended plan to start with: Lumo Free, €0. Prices checked on October 3, 2026 on the vendor’s official page.
LumoProton’s encrypted assistant, built for privacy- Vendor
- Proton (Switzerland)
- Free plan
- Yes
- Recommended plan
- Lumo Free, €0
- Page checked on
- October 3, 2026
What Lumo does
Who it’s for: people who handle sensitive information (HR, finance, legal, management) and those who want a European assistant with no ads.
Web search, with sources
Lumo looks up recent information on the web and says where it comes from. You can open each source to check.
Read a file and turn it into a chart
You attach a file, for example a CSV or Excel spreadsheet. Lumo reads it, answers your questions, and draws a chart in the conversation. You can ask for another type of chart, then download it.
Also
- Projects: one folder per topic
- Memory
- Ghost mode
- Create and edit an image
- Custom assistants
Lumo pricing
The Lumo Plus price is the one shown in the French App Store on October 3, 2026. On Proton’s website, the amount depends on the currency and the duration you choose: we were unable to record it, or the price of Lumo Professional.
| Plan | Price | Who it’s for |
|---|---|---|
| Lumo Free Recommended to start | €0 | Exploring, occasional use |
| Lumo Plus | €12.99 per month (€119.99 for 12 months) | Daily use |
| Lumo Professional | Price shown on Proton’s website, per user per month | Teams and companies |
What the free plan includes
Conversations, web search, file reading, memory, and ghost mode. With limits: a reduced number of messages, history kept for only 7 days, few images, restricted use of the “Max” level, and a single project.
Nova’s advice
Start for free: it’s enough to judge the quality of the answers on your real topics. Move to Lumo Plus if you often hit the limits or want to keep your conversations for more than 7 days.
A first try, in 3 minutes
Your data. Your conversations are encrypted. Proton cannot read them, keeps no logs, and does not use them to train the AI.
What it does less well
- Lumo does not give access to the ChatGPT, Claude, or Gemini models. On a very difficult task, compare its answer with another assistant’s before relying on it.
- On the free plan, your conversations are kept for only 7 days and you have a single project.
Have it reword a delicate messageLumo- Open lumo.proton.me and log in.
- Paste the prompt below into the input box, then add your draft after it.
- Press Enter. The answer is written in a few seconds.
- Ask for an edit in the same conversation: “Shorter” or “Firmer about the date.”
- Reread, fix a detail if needed, then copy the text into your email.
The prompt to copy
Here is the draft of a message to a coworker who turned in a file late. Rewrite it so it is clear, respectful, and factual. Keep it to three sentences at most and suggest a new due date.
Jobs that use Lumo
In the starter kit for one job.
Alternatives to Lumo
Euria
Another Swiss assistant, hosted by Infomaniak, with transcription of audio files.
Mistral Vibe
Mistral’s French assistant, if you want a European tool with more work features.
Duck.ai
To use several well-known assistants anonymously, with no account.
ChatGPT
If privacy is not your first criterion and you want the most complete assistant.
Frequently asked questions about Lumo
How much does Lumo cost?
Lumo Free: €0; Lumo Plus: €12.99 per month (€119.99 for 12 months); Lumo Professional: price shown on Proton’s website, per user per month. Prices checked on October 3, 2026 on the vendor’s official page.
Can you use Lumo for free?
Yes. Conversations, web search, file reading, memory, and ghost mode. With limits: a reduced number of messages, history kept for only 7 days, few images, restricted use of the “Max” level, and a single project.
What happens to my data with Lumo?
Your conversations are encrypted. Proton cannot read them, keeps no logs, and does not use them to train the AI.
What are the alternatives to Lumo?
Euria: Another Swiss assistant, hosted by Infomaniak, with transcription of audio files. Mistral Vibe: Mistral’s French assistant, if you want a European tool with more work features. Duck.ai: To use several well-known assistants anonymously, with no account. ChatGPT: If privacy is not your first criterion and you want the most complete assistant.
Official pages consulted
Page checked on October 3, 2026. Brands are named to identify the tools. No affiliation.