Compare Lumo by Proton vs ProWritingAid vs Capacities
| Feature | Lumo by Proton | ProWritingAid | Capacities |
|---|---|---|---|
| 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. | ProWritingAid helps writers improve grammar, style, and story structure with reports and AI rewrites. A free tier lets you start, and Premium plans add deeper critique tools for people finishing books and long documents. | Capacities is a notes and knowledge app built around objects and daily notes. The Basic plan stays free, and Pro adds AI assist so you can explore and connect ideas while keeping ownership of your knowledge base. |
| Pricing | Free $0; Lumo Plus $12.99/mo monthly or $9.99/mo billed yearly ($119.88/yr) | Free tier available; Premium about $30/mo monthly or $10/mo billed yearly ($120); Premium Pro about $36/mo monthly or $12/mo yearly; lifetime options listed | Basic free forever; Pro about $9.99/mo; Believer from about $12.49/mo |
| Main category | Chat assistants | Writing | Research and notes |
| Website | Visit Lumo by Proton | Visit ProWritingAid | Visit Capacities |
| Info last checked | October 17, 2026 | October 14, 2026 | October 13, 2026 |
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