Proton Lumo Review: I Tested Proton’s New European ChatGPT Alternative

Proton has made a significant leap into artificial intelligence with Lumo, their privacy-centered AI chatbot that offers a secure alternative to ChatGPT and other mainstream AI tools. The Swiss company behind Proton Mail and Proton VPN demonstrates that artificial intelligence doesn’t have to come at the cost of personal privacy.

A Fresh Face in the AI Arena

July 2025 marked the debut of Proton’s official launch of Lumo, an AI assistant that takes a fundamentally different approach to the privacy-functionality equation compared to tech giants. While companies like OpenAI, Google, and Microsoft harvest user data for model training and business purposes, Proton has chosen a completely different path: your conversations remain genuinely confidential.

This move makes perfect sense for a company that has built its reputation on encryption services for over a decade. With a user base exceeding 100 million people globally, Proton has already demonstrated that there’s substantial demand for privacy-focused technology. They’re now bringing this same philosophy into the realm of artificial intelligence.

Hands-On Experience with Proton Lumo

I decided to put it through its paces with some basic prompts. I was curious about creating my own Safari extension as an ad blocker (I asked it in Dutch):

Here’s what I received in response:

While this did result in a functional Safari extension, it unfortunately failed to block ads effectively. When I posed the same question to Claude and implemented its code, YouTube ads and many other advertisements were immediately blocked.

However, straightforward questions are handled quite well:

Open-Source Foundation and European Values

What sets Lumo apart most distinctively is its reliance on open-source language models. Rather than depending on proprietary systems from American or Chinese tech corporations, Lumo operates using models including:

• Mistral Nemo (French)
• OLMO 2
• OpenHands 32B (optimized for coding tasks)
• NVIDIA models for specialized functions

These models run exclusively from Proton’s European data centers, ensuring all data falls under stringent European privacy regulations. This isn’t a minor detail – it means your conversations aren’t subject to American surveillance legislation or Chinese data governance requirements.

Zero-Access Encryption: Built-In Privacy

Lumo’s security architecture sets it apart from competitors:

No server logs: Proton doesn’t retain any logs of your conversations on their servers. This differs fundamentally from ChatGPT or Google Gemini, which store all user interactions.

End-to-end encryption: Saved conversations can only be decrypted on your device. Even Proton itself cannot access your discussions – utilizing the same proven technology that secures Proton Mail.

Ghost Mode: A special feature where your conversation vanishes completely when you close the window. No traces, no history whatsoever.

No user data training: Your queries and documents are never utilized to improve the AI model, unlike virtually every other major AI service.

Full Features Without Privacy Trade-offs

Despite prioritizing privacy, Lumo delivers nearly all the capabilities expected from a modern AI assistant:

• Document analysis and summarization
• Code generation and debugging
• Email drafting and revision
• Creative writing assistance
• Web search capabilities (disabled by default for privacy)
• Integration with Proton Drive for encrypted file access
• Support for various file formats

The web search feature deserves particular attention: it’s disabled by default and utilizes privacy-respecting search engines when activated. Users maintain complete control over when Lumo can access the internet.

Performance and Improvements

August 2025 saw the release of Lumo 1.1, a substantial update that delivered impressive enhancements:

• 170% improvement in context comprehension
• 40% more accurate at producing functional code
• 200% better at tackling multi-step problems
• Enhanced web search results with reduced hallucinations

This rapid development cycle demonstrates Proton’s dedication to offering not just a privacy-conscious alternative, but one that can compete on capabilities.

Access and Pricing Structure

Lumo can be accessed through:

• Web interface at lumo.proton.me
• iOS and Android applications
• No account required for basic usage

Free tier: Limited chat sessions, basic uploads, shorter conversation history

Lumo Plus (about €10/month extra): Unlimited conversations, larger file uploads, extended history, priority processing:

Important Considerations

Not everyone shares the same enthusiasm. Some privacy advocates point out that Lumo isn’t technically fully end-to-end encrypted during processing (your query must be processed by the AI model, after all). Additionally, the fact that server-side components aren’t completely open source raises some questions.

There’s also the question of whether performance matches that of GPT or Claude (in my basic testing, not quite yet). Users sometimes notice differences with complex tasks, though this gap is narrowing rapidly.

Wider Implications

Lumo’s arrival comes at a pivotal time. With growing concerns about AI surveillance, data exploitation, and the concentration of AI power among a few American and Chinese corporations, Proton offers a crucial alternative. It proves that Europe can do more than just create strict privacy laws – it can also develop innovative technology that upholds these principles.

For organizations grappling with compliance issues around using AI for sensitive data, Lumo could be the solution. The guarantee that trade secrets won’t end up in training datasets is a critical factor for many companies considering AI tool adoption.

An Essential Alternative

Proton’s Lumo represents more than just another chatbot – it’s a declaration of principles. It demonstrates that we don’t need to sacrifice AI’s benefits for privacy. In an era where Big Tech leverages AI to accelerate surveillance capitalism, Lumo provides a refreshing alternative.

Is it flawless? No. Does it match GPT or Claude’s capabilities? Not entirely yet. However, for users who prioritize privacy, European values, and open-source technology, Lumo presents a serious option that will only improve with time.

The real question isn’t whether we need privacy-first AI – it’s whether we’re willing to accept minor functionality trade-offs in exchange for significantly greater control over our data. For an increasing number of users and businesses, that answer is a resounding ‘yes’.

In an age where our most private thoughts and corporate secrets are shared with AI assistants, this isn’t a luxury anymore – it’s become a necessity.

Last Updated on 10 September 2025