Lumo Free
$0
Limited free access, no credit card required
- Limited Max model usage
- limited messages and chat history
- limited image generations
- 1 Project
Lumo
Privacy-first AI assistant from Proton with zero-access encrypted chats and no logging
Freemiumlumo.proton.meUpdated
About Lumo
Lumo is an AI assistant built by Proton, the Swiss company behind Proton Mail, Proton VPN and Proton Drive. It handles everyday assistant tasks such as answering questions, searching the web, analyzing uploaded files and images, generating images, and drafting or reviewing text and code. Proton positions it as a privacy-focused alternative to mainstream chatbots: conversations are protected with zero-access encryption, Proton says it keeps no logs of prompts or replies, and it says user data is never used to train models. The service is free to try as a guest, and a paid Plus plan raises usage limits.
Best for
- Everyday AI chat, web-assisted questions, document and image work without conversation logging or training on user data
- Private Research Questions: Ask sensitive questions with web search without chats being logged or used for training.
- Document and Image Analysis: Upload files or images, or link Proton Drive content, and ask for summaries or explanations.
- Writing and Code Review: Draft, edit or review text and code inside a Project that holds related context.
- Reusable Task Assistants: Create Custom Lumos for recurring jobs such as formatting research answers.
Not ideal for
- Users who need the largest frontier models, a public developer API, a desktop app
Popular with
- Privacy-conscious individuals
- Existing Proton users
- Journalists and researchers
- Small teams handling sensitive information
Screenshots
Key features
- Zero-Access Encrypted Chats
- Open-Source Models
- Web Search
- Image Generation and Editing
- Projects
- Custom Lumos
- Proton Drive Integration
- Guest Mode
- Memory and Personalization
Pros and cons
Pros
- Zero-access encryption on saved chats, with a stated no-logging policy.
- Open-source code and open-source models that can be inspected.
- Permanent free tier with guest access and no credit card.
- Web, iOS and Android apps.
- Run by Proton AG, a Swiss company, and stated to comply with GDPR.
Cons
- Free chat history is kept for only 7 days.
- Uses open-source models rather than the proprietary frontier models of larger rivals.
- No desktop app or public API found.
- Lumo Plus limits are described only as "more" than Free, not as numbers, and the plan costs $12.99/month ($9.99/month billed annually).
Pricing
Plans as listed by the vendor on . Check their site for current prices.
Lumo Plus
Most popular$12.99/month
Individuals who want higher limits
- More Max model usage
- more messages and chat history
- more image generations
- unlimited Projects
- unlimited Custom Lumos
Our ratings
Scored out of 10 by the Finder Atlas editorial team.
7.6overall
- Ease of Use
- 8.5
- Feature Depth
- 7.0
- Value for Money
- 7.5
- Performance & Speed
- 7.2
- Documentation & Support
- 7.8
Platforms and integrations
Available on
- Web
- iOS
- Android
Works with
- Proton Drive
Lumo alternatives
Other tools people compare with Lumo.
- Compare
Duck.aiFreemiumChat with ChatGPT, Claude and other AI models without handing over your data
- Compare
DeepSeekFreemiumFree AI chat app and low-cost API running DeepSeek's open-weights V4 models
- Compare
Anthropic's AI assistant for writing, analysis, coding and working with files
- Compare
QwenFreemiumAlibaba's free AI assistant and open-weight model family, on web, mobile and API
- Compare
Mistral Vibe (formerly Le Chat)FreemiumMistral AI's chat assistant and coding agent for everyday work and software tasks
Release history
Added Fast and Thinking modes, image generation and recognition, stronger web search, memory, a larger context window...
Added Fast and Thinking modes, image generation and recognition, stronger web search, memory, a larger context window and Custom Lumos, per MacRumors.
Reviews
No reviews yet
Used Lumo? Help others decide by sharing your experience.
Frequently asked questions
Is Lumo free?
Yes. Lumo Free has limited model usage, messages, chat history and image generations, plus one Project, and needs no credit card. Lumo Plus is a paid upgrade.
Does Lumo use my chats to train AI models?
Proton says it never uses user data to train models and keeps no logs of prompts or replies. The exception noted on its privacy page is anonymized feedback on Apertus 1.5 responses, which users must choose to submit.
Which AI models does Lumo use?
Open-source models optimized by Proton. Its privacy page lists Qwen 3.5, GLM 5.3, Image-Turbo, FireRed-Image-Edit-1.1 and Apertus 1.5. They run on servers Proton controls.
Do I need a Proton account?
No for limited guest access. A Proton Account is needed to save chat history across devices and to use Projects and paid plans.
Is there a mobile app?
Yes, Lumo has iOS and Android apps in addition to the web app.
How long are chats kept?
On the free plan, Proton's help page says chats are saved for 7 days only. Guest conversations are erased when the session ends.
More AI Assistants tools
View allClaude
AI Assistants
Anthropic's AI assistant for writing, analysis, coding and working with files
Freemium4.5
DeepSeek
AI Assistants
Free AI chat app and low-cost API running DeepSeek's open-weights V4 models
Freemium
Gemini Notebook
AI Assistants
Google's Gemini Notebook, formerly NotebookLM, answers questions and builds summaries from your own sources
Freemium
