Proton's New AI Assistant Lumo Offers Encrypted Chat Alternative

Wednesday July 23, 2025 4:16 am PDT by Tim Hardwick

Proton today launched Lumo, an AI assistant that promises to keep your conversations completely private. Best known for its encrypted Mail and VPN services, the Swiss company says it built Lumo as an alternative to mainstream AI tools that typically capitalize on users' data by using it to train their large language models (LLMs).

12 Lumo Proton
Lumo can be used just like other AI chatbots (Open AI's ChatGPT or Google Gemini, for example) so it can do things like analyze documents, rewrite emails, and generate code. Proton says Lumo doesn't keep chat logs on its servers, and everything stays encrypted on your device using the same technology that protects the company's other services, so no one else can read your conversations – including Proton itself.

The service runs on open-source AI models like Mistral's Nemo and Nvidia's OpenHands 32B. The models operate from European data centers that Proton says it controls directly. Users' questions and responses don't get fed back into the system to train future versions, so there's no risk of your private information showing up in someone else's chat.

Lumo includes a "Ghost mode" that makes your current conversation disappear forever when you close it, while the assistant's web search feature (if you turn it on) uses privacy-friendly search engines. You can also link Proton Drive files to Lumo and everything stays encrypted.

Lumo is free to use at Lumo.proton.me and does not require a Proton account when accessed. However, if you have a Proton account, your chat history can be saved using the company's "zero-access" encryption across all your devices. There are also mobile apps for iPhone and Android.

For power users, Lumo Plus costs $12.99 per month and removes limits on chats and file uploads. Announcing the chatbot, Proton CEO Andy Yen said the company built Lumo because AI shouldn't become the world's most powerful surveillance tool. "For this reason, we believe it is essential to provide an alternative that protects privacy and serves users as opposed to exploiting them."

Lumo by Proton is available to download from the App Store. [Direct Link]

Tag: Proton

Top Rated Comments

GrumpyOldGuy52

16 months ago

Proton is sooo overrated. Many sites say the company is “privacy-focused”, yet after signing up there for a throwaway email I realized they blocked me from receiving mails for “security reasons” and that I need to provide my phone number (which I don’t want to). I just wanted to use it to sign up on Facebook. And now they have made their own Bonzi Buddy? Nah I better continue using my iCloud accounts

If you were using Proton for a throwaway email, then they were right to block you. The service isn't designed for that, and they police accounts that look spammy. If you use them as a legit email service, then you have options to create those throwaway email addresses you want (like the aliases in iCloud).

I, for one, appreciate the work they're doing, but to each their own.

Score: 7 Votes (Like | Disagree)

DestructoTim

16 months ago

Proton is making mistakes. The mainstream doesn’t know who they are yet, but they keep making changes and additions that core users don’t want. That is how you kill your company.

Score: 7 Votes (Like | Disagree)

senttoschool

16 months ago

Can't wait until an average Apple Silicon Mac can run decent models locally. Much more privacy than something hosted in the cloud like Proton.

Hoping M5 generation of chips have Tensor-core acceleration in its GPUs. Macs have unified memory which is great for LLMs but they lack matrix acceleration in GPUs for faster prompt processing.

Score: 6 Votes (Like | Disagree)

Marco Klobas

16 months ago

As a Proton user I'd like them to be more focused on improving and fixing their current services rather than adding new ones. It's a common criticism shared among its user base.

That said, I don't bash completely the idea or the company as a whole like others have in the comments above. I respect way more Proton than, say, the so "praised" OpenAI. ChatGPT might be superior – I don't like at all who is leading it, though (Sam Altman). The same goes for Meta, just to name another big protagonist in this crazy AI race.

Heck, I even preferred to try the criticized Grok (or, should I say, its founder), rather than mingling with OpenAI and Meta. Gemini seems to me not bad, too – especially for basic use. Sure, it's Google, blah, blah – still less fishy than Zuckerberg, Altman, et similia, IMO.

We'll see how will it end. My feeling is that a quite big part of the AI phenomenon is an inflated bubble. The very fact that basically all of them started almost immediately asking money (subscriptions – which, relatively speaking, are not even affordable), it suggests me that the expenses are huge and monetization is desperately needed.

For some specific tasks (professionals) it's a useful tool worth the price. I have doubts regular people will embrace it in hordes, especially considering the asked price.

I'm not against the pay-per-service concept. On the contrary. Actually, I'd have requested a contribution to the internet user base years ago even for a "simple" yet fundamental crawling/browsing service like Google (which, coincidentally, is going to be replaced by AI prompts). Unpopular opinion, I know...

Average people are unfortunately too accustomed to the "everything is free on internet" idea. A mistake made in the past years.

Anyway, I might be wrong. Who knows.

Score: 3 Votes (Like | Disagree)

Bazza1

16 months ago

Nope.
See also every other company crawling onto this very expensive - and for most average consumers, pointless - bandwagon. This includes other supposed 'privacy-focussed' companies like Duck Duck Go and Mozilla's Firefox.
If you have to create software to justify its use (see Apple), you know you're in trouble. When will shareholders realize their profits are going into the computer equivalent of 3D TV?

Score: 2 Votes (Like | Disagree)

iPay

16 months ago

$ Hey Lumo, why did Proton make an AI bot in the first place?
> Because everybody does! We can't miss the boat like some other companies.

$ Sure. But you don't use my data, do you?
> (clicks) I'm focused on giving you the most pleasant and relevant experience.

$ I see. But how can you rewrite my mails if you can't read them?
> Privacy has many meanings. Moreover, any personal data is totally anonymized before feeding the Great Data Forge

Score: 2 Votes (Like | Disagree)

Read All Comments

Proton's New AI Assistant Lumo Offers Encrypted Chat Alternative

Popular Stories

Developers Question Scope of Potential Apple Antitrust Settlement

Here's What Apple's Apps Look Like on the iPhone Duo

Apple Pulls Keynote, Pages and Numbers From App Store [Update: Back]

Top Rated Comments

Next Article

Videos

Guides

Upcoming

Other Stories