🔎 Research & answers
Deep research agents and answer engines that read the web and your docs for you.
How we rank: editorial order informed by public signals shown on each card (GitHub stars for open-source tools, notable adoption otherwise). Rankings are never for sale; paid placements appear only in the labeled Featured slot.
ChatGPT
Freemium · from $20/moOpenAI's assistant with deep research, agent mode and writing tools.
Why people use it: Deep research mode browses dozens of sources and writes a cited report.
Perplexity
Freemium · from $17/moAI answer engine with cited sources and deep research.
Why people use it: Every answer comes with sources, so it's fast to fact-check.
Gemini
FreemiumGoogle's AI assistant with Deep Research and Workspace integration.
Why people use it: Deep Research plus direct access to your Gmail, Docs and Drive.
NotebookLM
FreemiumUpload your sources and get answers, notes and audio overviews.
Why people use it: Answers grounded only in docs you upload, plus podcast-style audio summaries.
GPT Researcher
FreeOpen-source autonomous agent for deep research reports.
Why people use it: Self-hosted deep research agent you can customize and embed.
Elicit
FreemiumAI research assistant for searching and summarizing academic papers.
Why people use it: Built for literature reviews: finds papers and extracts findings into tables.
Exa
Freemium · from Pay as you goWeb search API built for AI agents, with contents, deep-research and MCP access.
Why people use it: Gives your agent or app real web search results and page contents, so its research is grounded in current sources.