Compare Duck.ai vs ProWritingAid vs Capacities
| Feature | Duck.ai | ProWritingAid | Capacities |
|---|---|---|---|
| Description | Duck.ai is DuckDuckGo private AI chat. It helps you ask questions and draft answers without building an advertising profile around your prompts, so you can get help while keeping everyday browsing privacy habits. | 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 private AI chat (DuckDuckGo Duck.ai) | 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 Duck.ai | Visit ProWritingAid | Visit Capacities |
| Info last checked | October 14, 2026 | October 14, 2026 | October 13, 2026 |
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