Free plans compared
Best Free AI Research Tools (2026)
AI research tools search papers, summarize sources and answer questions with citations. Free plans often limit searches, papers or advanced models. This guide separates tools that answer from the open web from tools built for academic papers, so you can choose by task.
Disclosure: some Visit links may be affiliate links, and we may earn a commission at no extra cost to you. Details come from official pricing and product pages, last reviewed 2026-10-15; this is not a hands-on test. Confirm current limits with the provider.
What to check before you choose
- Does it cite sources you can open and check?
- Does it search the open web, academic papers or only files you upload?
- How many searches or documents does the free plan allow?
- Can you export citations or notes?
How we chose: tools listed here have an active product, a free plan or free tier, and pricing we could confirm from the provider. Retired or paid-only tools are left out automatically.
Quick comparison of free plans
| Tool | Free plan | No card needed | Platforms |
|---|---|---|---|
| Perplexity | Standard (free): 3 Pro Searches per day, 1 research query per month, practically unlimited basic searches, limited file uploads; no advanced AI models, file/app creation… | — | Web |
| Gemini Notebook | Standard is free with a Gmail account: up to 100 notebooks per user and 50 sources per notebook (Plus 200/100, Pro 500/300, Ultra 500/500 or 600). | — | Web |
| Elicit | Basic is free with search and summaries, but limited Research Agent and report usage. | — | Web |
| Semantic Scholar | The research search service is free. A free account enables library features; it does not unlock every publisher’s full text. | — | Web |
| Connected Papers | The free tier includes five graphs/month with all features. | — | Web |
| ResearchRabbit | The current official site offers free signup and access. | — | Web |
| Paperguide | A continuing Free plan includes monthly AI credits and restricted search, reference and extraction capacity. | — | Web |
| Anara | Anara has a continuing Free plan with a daily usage allowance. | — | Web |
| Explainpaper | The continuing Free plan covers highlight explanations and follow-ups using basic models. | — | Web |
| SciSpace | The pricing page lists Premium at $20 a month ($12 a month billed annually, 1,200 monthly credits), Advanced at $90 ($70 annually) and Max at $200 ($160 annually), with… | — | Web |
The tools, in detail
AI search and research assistant that returns source-linked answers, with free and paid research options.
Best for: Source-linked web research and questions
Free plan: Standard (free): 3 Pro Searches per day, 1 research query per month, practically unlimited basic searches, limited file uploads; no advanced AI models, file/app creation, image generation or Comet Assistant queries. API is pay-as-you-go with no complimentary credits.
Key features
- Source-linked answers
- Web search
- Research tools
- Model choice on eligible plans
Limits to know
- Standard is free with basic access and limited advanced usage. Paid plans increase research and model allowances; API usage is billed separately.
- Citations are starting points: a real URL can still support a different claim.
Google's source-based notebook assistant for understanding documents and developing research-oriented outputs.
Best for: Source-grounded study and research notebooks
Free plan: Standard is free with a Gmail account: up to 100 notebooks per user and 50 sources per notebook (Plus 200/100, Pro 500/300, Ultra 500/500 or 600). Daily quotas reset after 24 hours and monthly quotas after 30 days; limits are subject to change.
Key features
- Source-based questions
- Document analysis
- Notebook organisation
- Research outputs
Limits to know
- Standard access is available with eligible Google accounts. Google AI and Workspace plans add capacity; feature and notebook limits depend on the account.
- Source selection limits the answer; missing or outdated documents remain your responsibility.
Research assistant for finding papers, extracting evidence, synthesising findings, and structured literature-review workflows.
Best for: Finding and structuring evidence from research papers
Free plan: Basic is free with search and summaries, but limited Research Agent and report usage. Paid tiers add export, extraction, and review capacity.
Key features
- Paper search
- Source-linked summaries
- Evidence tables
- Research reports
Semantic Scholar is Ai2’s free AI-powered academic search service.
Best for: Academic search and contextual paper reading
Free plan: The research search service is free. A free account enables library features; it does not unlock every publisher’s full text. Semantic Reader availability varies by paper.
Key features
- Academic paper search
- Paper metadata
- Citation links
- Saved library
Limits to know
- Full-text access depends on the publisher and available copies
- Semantic Reader features are limited to supported papers and fields
Connected Papers creates similarity graphs around academic papers and offers prior and derivative work views.
Best for: Similarity graphs around academic seed papers
Free plan: The free tier includes five graphs/month with all features. Academic and Business Premium plans remove the graph limit; select the plan matching personal, academic or commercial use.
Key features
- Similarity graphs
- Seed-paper input
- Prior works
- Derivative works
Limits to know
- Similarity links are not the same as direct citation relationships
- Five free graphs per month may be insufficient for broad review work
ResearchRabbit recommends related academic work from papers in your collection and visualises research connections.
Best for: Exploring related papers and research networks
Free plan: The current official site offers free signup and access. No specific paid plan or unlimited corpus completeness is claimed here; check the app for current account conditions.
Key features
- Paper collections
- Similar-paper discovery
- Citation exploration
- Author networks
Limits to know
- A recommendation is not proof of relevance or study quality
- Database coverage and metadata gaps can leave out relevant research
Search papers, chat with PDFs, manage references, and extract research data into structured tables.
Best for: Paperguide suits researchers moving from a reading question toward organized evidence and a cited draft.
Free plan: A continuing Free plan includes monthly AI credits and restricted search, reference and extraction capacity. Paid plans expand tables, collaboration, reports and systematic-review features. Some extraction features are labelled coming soon; check availability rather than assuming every advertised workflow is already included.
Key features
- AI paper search
- PDF conversations
- Reference manager
- Structured data extraction
Limits to know
- Free storage and extraction capacity are limited
- Generated reports require source-level verification
A research workspace for literature search, document questions, evidence tables, and source-linked writing.
Best for: Anara, formerly Unriddle, suits researchers organizing papers and turning a bounded question into an evidence trail.
Free plan: Anara has a continuing Free plan with a daily usage allowance. Paid plans expand usage and research modes. The current billing guide explains limits and library connections; a free account does not provide unrestricted deep research.
Key features
- Scientific literature search
- Document library questions
- Passage-level citations
- Evidence table exports
Limits to know
- Free usage is capped daily
- A synthesis still requires original-paper verification
Highlight difficult passages in research papers and get explanations, follow-up answers, and optional figure analysis.
Best for: Explainpaper suits readers trying to understand a dense passage while staying close to the paper.
Free plan: The continuing Free plan covers highlight explanations and follow-ups using basic models. Paid access adds advanced models, figure or equation explanations, outlines and saved work. Check the current plan before relying on those richer reading tools.
Key features
- Highlighted-passage explanations
- Follow-up questions
- Paper upload workflow
- Zotero library import
Limits to know
- Advanced figure and paper-analysis tools are paid
- An explanation can simplify away an important assumption
AI research workspace for exploring papers, chatting with PDFs, extracting information, and developing literature reviews.
Best for: Paper discovery and PDF questions
Free plan: The pricing page lists Premium at $20 a month ($12 a month billed annually, 1,200 monthly credits), Advanced at $90 ($70 annually) and Max at $200 ($160 annually), with a 24-hour money-back guarantee. It does not list a free plan, so check what signing up gives you before relying on free access.
Key features
- Paper discovery
- PDF questions
- Literature reviews
- Data extraction
Limits to know
- Free entry and paid access are offered, but exact current quotas were not exposed in readable pricing content. Some agent and extraction work consumes credits.
Head-to-head comparisons
Frequently asked questions
Can I trust AI research summaries?
Open the cited sources and confirm the claim appears there. Treat the summary as a map to the sources, not a replacement for reading them.
What is the difference between a research assistant and a chatbot?
Research tools focus on finding and citing sources. Chatbots answer from general knowledge and may not show where an answer came from.
Which research tools here need no credit card?
We have not confirmed a no-card sign-up for tools in this list. Check each provider's sign-up page, and see our guide to free AI tools with no credit card required.
How current is this list?
Tool details were last reviewed 2026-10-15 from official pages. Free plans change often, so check the linked pricing page before you rely on a limit.