Best AI tools to research a topic with sources

Short answer

Perplexity ranks #1 for research a topic with sources (score 9.7/10). Pricing: $17/mo (Pro, billed annually); free tier: yes. Runners-up: Gemini, Gemini Notebook (formerly NotebookLM).

Top 5, ranked by our published rubric. Sponsorship never affects the order. Last updated 2026-10-13.

Compare the top 5 side by side
#ToolScorePricingPaid fromFree tierWhat it is
1Perplexity9.7Free tier$17/mo (Pro, billed annually)yesAI answer engine with citations
2Gemini8.5Free tierAI Plus $4.99/mo (AI Pro $19.99/mo)yesGeneral AI assistant by Google
3Gemini Notebook (formerly NotebookLM)8.0UnverifiedUnverifiedUnverifiedResearch notebook grounded in your sources
4ChatGPT7.8Free tierGo $8/mo (Plus $20/mo)yesGeneral AI assistant by OpenAI
5You.com6.7Free tier$5 per 1K calls (usage-based API)yes (API free credit)AI-ready web search APIs

AI answer engine with citations

Score 9.7/10Paid from: $17/mo (Pro, billed annually)Free tier: yesLast verified 2026-10-13

Why ranked: Perplexity: AI answer engine with citations. We placed it 1st of 5 on fit for this task. Free tier; paid from $17/mo (Pro, billed annually).

Fit 10.0 Β· value 10.0 Β· breadth 10 Β· availability 7 (how we score) Β· pricing source Β· site bot-blocked (403)

General AI assistant by Google

Score 8.5/10Paid from: AI Plus $4.99/mo (AI Pro $19.99/mo)Free tier: yesLast verified 2026-10-13

Why ranked: Gemini: General AI assistant by Google. We placed it 3rd of 5 on fit for this task. Free tier; paid from AI Plus $4.99/mo (AI Pro $19.99/mo).

Fit 7.0 Β· value 10.0 Β· breadth 10 Β· availability 10 (how we score) Β· pricing source Β· site live

Research notebook grounded in your sources

Score 8.0/10Paid from: UnverifiedFree tier: UnverifiedLast verified 2026-10-13

Why ranked: Its own site says: β€œUse the power of AI for quick summarization and note taking, Gemini Notebook is your powerful virtual research assistant rooted in information you can trust.” We placed it 2nd of 5 on fit for this task. Pricing unverified.

Fit 8.5 Β· value 5.0 Β· breadth 10 Β· availability 10 (how we score) Β· no readable pricing page Β· site live

SPONSORED Your tool here: paid placement is shown here, separate from the ranking, and never changes the order. Advertise

General AI assistant by OpenAI

Score 7.8/10Paid from: Go $8/mo (Plus $20/mo)Free tier: yesLast verified 2026-10-13

Why ranked: Its own site says: β€œUse ChatGPT to answer questions, write, create images, complete work, and codeβ€”all in one place.” We placed it 4th of 5 on fit for this task. Free tier; paid from Go $8/mo (Plus $20/mo).

Fit 5.5 Β· value 10.0 Β· breadth 10 Β· availability 10 (how we score) Β· pricing source Β· site live

AI-ready web search APIs

Score 6.7/10Paid from: $5 per 1K calls (usage-based API)Free tier: yes (API free credit)Last verified 2026-10-13

Why ranked: Its own site says: β€œSkip the groundwork with our AI-ready Web Search APIs, delivering advanced search capabilities to power your next product.” We placed it 5th of 5 on fit for this task. Free tier; paid from $5 per 1K calls (usage-based API).

Fit 4.0 Β· value 10.0 Β· breadth 8 Β· availability 10 (how we score) Β· pricing source Β· site live

FAQ

What is the best AI tool to research a topic with sources?

By TaskRanking's published rubric, Perplexity ranks first, followed by Gemini and Gemini Notebook (formerly NotebookLM).

Is there a free AI tool to research a topic with sources?

Yes: Perplexity has a free tier per its own pricing page (checked 2026-10-13).

How are these tools ranked?

Score = 50% fit, 25% value (from vendor pricing pages), 15% breadth, 10% availability. Sponsorship never affects rank.

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