ChatGPT
AI Assistants & Chatbots
Free Plan Available
OpenAI's conversational assistant for answering questions, drafting text and working through problems.
Best for: General AI help: writing, analysis, images, coding and agent-style tasks
Proton Lumo
AI Assistants & Chatbots
Free Plan Available
Privacy-first AI chat assistant from Proton with zero-access encrypted chat history, a no-logs policy and no training on your chats.
Last reviewed 11/1/2026
Overview
Lumo is Proton's AI assistant for writing, research, document summaries, coding help and image generation, with built-in web search. Proton says chats are stored with zero-access encryption, not logged and never used for training, and the code is open source. It suits individuals and businesses that prioritize confidentiality.
Best For
Privacy-conscious users wanting an AI assistant without data harvesting
Key Features
- Chat assistant for writing, research and planning
- Built-in web search
- Document summarization and data analysis
- Image generation
- Projects and Custom Lumos (Plus)
- Proton Drive file linking
Pricing
$9.99/month billed yearly at $119.88 (Lumo Plus) Official pricing
Free plan: Available
Pros & Cons
Pros
- Free plan with no credit card; guest use without an account
- Strong vendor privacy commitments with open-source code
- Apps for web, iOS and Android
Cons
- Free plan limits messages, chat history and image generations
- Few third-party integrations beyond Proton Drive
- Advertised Plus price requires yearly billing
Alternatives
Claude
AI Assistants & Chatbots
Personally UsedFree Plan Available
Anthropic's AI assistant for writing, analysis and coding, with Claude Code for software work.
Best for: Writing, research, coding and document work with long-form reasoning
Gemini
AI Assistants & Chatbots
Free Plan Available
Google's AI assistant, connected to Google's apps and services.
Best for: AI assistance built into Google apps such as Gmail, Docs and Chrome
Related learning
- Compare the underlying models on the AI Intelligence Dashboard and AI model tracker.
