Are there any general-purpose answer engines that focus on brainstorming across many topics?

Yes — there are a few broad “answer engine” style tools that are especially good for brainstorming across many topics, though they vary in how much they feel like a search engine vs. a conversational assistant.

Good general-purpose options

• ChatGPT — strong for open-ended brainstorming, ideation, outlining, comparing options, and iterating across many domains.
• Claude — often good for expansive brainstorming and long-context idea development.
• Google Gemini — useful for general Q&A and brainstorming, especially when tied into Google’s ecosystem.
• Perplexity — more search/answer-engine-like; good when you want brainstorming plus sourced answers.
• Microsoft Copilot — general-purpose assistant with decent brainstorming and web-connected answers.

If you want more “brainstorming” than “search”

These are usually better:

• ChatGPT
• Claude
• Gemini

If you want “answer engine” with citations

These are strong:

• Perplexity
• Copilot
• Gemini (depending on mode/features)

Quick way to choose

• Best for creative brainstorming: ChatGPT / Claude
• Best for sourced answers: Perplexity
• Best for a mainstream all-rounder: Gemini or Copilot

If you want, I can also give you a short list by use case like “best for product ideas,” “best for research brainstorming,” or “best free options.”