About Lumo, the privacy-first AI assistant | Lumo by Proton

What is Lumo

Lumo is a confidential AI chat assistant developed by Proton, the organization behind Proton Mail, Proton VPN, and the Proton Foundation. Positioned as a "privacy-first" alternative to mainstream AI tools, Lumo addresses growing concerns regarding data harvesting, profiling, and the use of user conversations for training commercial AI models. The service is built in Europe and operates under strict GDPR regulations, ensuring that user data remains under the sole control of the individual.

Unlike many popular AI chatbots that store conversation history to improve their algorithms or serve targeted advertisements, Lumo employs a "no-logs" policy combined with zero-access encryption. This means that while Proton hosts the infrastructure, it technically cannot read, access, or store the content of user chats in a way that allows decryption without the user's specific key. The platform is available across multiple devices, including web browsers, iOS, and Android, providing a consistent experience for users prioritizing digital freedom and security.

Key features

Zero-Access Encryption and No-Logs Policy The core differentiator of Lumo is its security architecture. All conversations are encrypted such that Proton cannot access them. This ensures that sensitive information shared during chats—whether related to health, work, or personal ideas—is never used to build user profiles, target ads, or sold to third parties. The source confirms that Lumo does not use user data to train its AI models, a practice common among competitors.

Open Source Transparency Trust is established through transparency. Lumo’s code is fully open source, allowing independent developers and security experts to audit the software. This verification process confirms that the privacy claims are technically sound and that no backdoors exist for data extraction. Users can explore Lumo’s code directly to verify its security standards.

Personalization with "Custom Lumos" For users seeking tailored experiences, Lumo offers "Custom Lumos." These allow users to create personalized AI agents with specific instructions or personas. This feature is particularly useful for maintaining context in specialized tasks without exposing raw data to the underlying model providers in a way that compromises privacy.

Image Generation Beyond text-based assistance, Lumo supports image generation capabilities. Users can create visual content within the secure environment, ensuring that creative assets and prompts remain private.

Cross-Platform Availability Lumo is accessible via a web app, as well as native mobile applications for iOS and Android. This multi-platform approach ensures that privacy-focused AI assistance is available regardless of the device ecosystem the user prefers.

Business Solutions Proton extends these privacy guarantees to the enterprise sector through Lumo for Business. This tier is designed for professionals and teams who require confidential AI assistance for sensitive corporate communications, compliant with high-security standards including HIPAA, GDPR, and ISO 27001.

Use cases

Secure Professional Research Professionals in legal, medical, or financial sectors can use Lumo to draft documents, summarize reports, or analyze data without risking the leakage of confidential client information. The zero-access encryption ensures that proprietary data never leaves the user's control in plaintext.

Personal Health and Wellness Users discussing health symptoms, mental wellness, or personal advice can do so without fear of their data being harvested for insurance profiling or advertising. Lumo’s privacy-first stance makes it a safe space for sensitive personal inquiries.

Creative Development Writers, designers, and developers can use Lumo for brainstorming and coding assistance. The ability to generate images and receive text-based feedback within an encrypted environment protects intellectual property and creative concepts from unauthorized use.

Team Collaboration Businesses can utilize Lumo for Business to enable team-wide AI assistance while maintaining organizational data sovereignty. The platform supports the creation of custom workflows that adhere to corporate security policies.

Pricing overview

Lumo operates on a freemium model, allowing users to start with a free tier or upgrade for enhanced capabilities.

Free Plan The free version provides limited access to the Max model, restricted message counts, limited chat history, and a single project allowance. It serves as an entry point for users to test the privacy features without financial commitment. No credit card is required to sign up.

Plus Plan The Plus plan unlocks advanced features, including unlimited chats, more image generations, unlimited projects, and the ability to create Custom Lumos. The source indicates a monthly billing structure with a 30-day money-back guarantee. Specific pricing figures in local currencies (CHF, EUR, USD) are mentioned but exact dollar amounts vary by region and billing cycle (monthly vs. yearly). Users are advised to check the official pricing page for current rates.

Business Plans For enterprise needs, Proton offers dedicated business plans. These are tailored for organizations requiring HIPAA compliance and higher security thresholds. Pricing for business plans is not explicitly detailed in the general source material and requires direct inquiry or consultation with Proton sales.

Who should use it

Lumo is ideal for individuals and organizations who prioritize data privacy above all else. This includes:

• Privacy Advocates: Users already familiar with Proton’s ecosystem who seek to extend their privacy habits to AI interactions.
• Professionals Handling Sensitive Data: Lawyers, doctors, and financial advisors who cannot risk data breaches or non-compliance with regulations like HIPAA or GDPR.
• Creative Professionals: Individuals who want to leverage AI for content creation without their ideas being used to train public models.
• Enterprise Teams: Organizations looking for a secure, auditable AI solution that integrates with existing security frameworks.

For those interested in exploring more privacy-focused tools, you can browse our ToolSeekAI tools directory. Additionally, compare Lumo against other major AI assistants like Gemini or Claude using our rankings to understand its position in the market.

Evaluation Context

Onboarding Flow: The onboarding process is straightforward, requiring only an email address to create an account. The absence of mandatory credit card information for the free tier lowers the barrier to entry. However, the exact steps for verifying identity or setting up two-factor authentication are not confirmed in the source, though Proton typically emphasizes strong security practices.

Integration Considerations: Lumo currently functions as a standalone chat application. There is no confirmed information regarding API integrations with third-party productivity suites (e.g., Microsoft Office, Google Workspace) in the provided source. Users should verify if direct imports/exports of encrypted chats are supported for backup purposes.

Data/Privacy Questions: A critical question for potential users is whether data is deleted upon account closure. The source states that users can delete their account at any time and that Lumo complies with GDPR, implying the right to erasure. However, the exact mechanism for permanent data deletion across distributed encryption keys is not confirmed in the source.

Pricing Verification Checklist:

• Confirm current monthly/yearly costs for Plus plan.
• Verify if "unlimited" has fair usage policies.
• Check if business plans include SLAs (Service Level Agreements).

Comparison Criteria: When comparing Lumo to other AI tools, consider the trade-off between feature richness and privacy. While competitors may offer more advanced multimodal capabilities or larger model contexts, Lumo’s primary value proposition is the guarantee that your data is never used for training or profiling.

FAQ

Is Lumo really private? Yes. Lumo uses zero-access encryption, meaning Proton cannot read your chats. The code is open source for independent verification.

Does Lumo use my data to train AI models? No. Lumo explicitly states that it does not use user conversations to train its AI models.

What is the difference between Free and Plus plans? The Free plan offers limited messages and one project. The Plus plan provides unlimited chats, more image generations, unlimited projects, and Custom Lumos.

Can I use Lumo for business? Yes, Lumo offers a specific plan for Business that supports teams and professionals, with compliance for standards like HIPAA and GDPR.

Is Lumo available on mobile? Yes, Lumo has native apps for iOS and Android, as well as a web app.

How do I delete my account? Users can delete their account at any time through the settings, in compliance with GDPR rights.

Pros

• Zero-access encryption ensures true privacy.
• Open-source code allows for independent security audits.
• Does not use user data to train AI models.
• Compliant with GDPR and other strict privacy regulations.
• Available on web, iOS, and Android platforms.

Cons

• Free plan has significant limitations on usage and features.
• Specific pricing for business plans is not publicly detailed in the source.
• Lacks confirmed integration with third-party productivity tools.
• Image generation capabilities may be less advanced than competitors.
• Onboarding and data deletion mechanisms are not fully detailed in the source.