Compare Lumo by Proton vs Grammarly vs Open Notebook
| Feature | Lumo by Proton | Grammarly | Open Notebook |
|---|---|---|---|
| Description | Lumo is Proton's AI assistant for questions, writing help, and file chats, built so your conversation history stays encrypted and private. A free plan lets anyone try it, and Plus adds unlimited chats for people who want privacy-first help every day. | AI writing assistant for clarity and correctness | An open-source NotebookLM-style app for researching, summarizing and chatting with your sources. Built for: Researchers, writers and learners who want a private NotebookLM alternative. Format: Self-hosted web app (Docker). License: MIT. Open source on GitHub (40,067 stars as of 2026-10-11). |
| Pricing | Free $0; Lumo Plus $12.99/mo monthly or $9.99/mo billed yearly ($119.88/yr) | $12/month | Free and open source; self-hosting, model or API costs may apply |
| Main category | Chat assistants | Writing | Research and notes |
| Website | Visit Lumo by Proton | Visit Grammarly | Visit Open Notebook |
| Info last checked | October 17, 2026 | October 12, 2026 | October 12, 2026 |
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