SRC-01Free plan
Perplexity
Used for
AI search engine that answers questions with numbered sources you can click and verify.
Best for: Research with citations
SRCFree Search & Research tools
Answers with sources, paper discovery and research on your own documents.
How to choose
Use Perplexity or You.com for everyday questions where you want sources. For school and academic work, go straight to Semantic Scholar, Consensus or Elicit so your citations come from real papers. NotebookLM is the best choice when the answer should come only from documents you already have.
SRC-02100% Free
NotebookLM
Used for
Upload PDFs, notes, websites or YouTube links and get answers, summaries, study guides and audio overviews grounded in your sources.
Best for: Studying and summarizing your own files
SRC-03Free plan
Consensus
Used for
Searches peer-reviewed scientific papers and summarizes what the research says on a question.
Best for: Evidence from scientific studies
SRC-04Free plan
Elicit
Used for
Research assistant that finds academic papers, extracts key findings and builds summary tables.
Best for: Literature reviews and theses
SRC-05100% Free
Semantic Scholar
Used for
Free AI-powered search engine for academic papers with TLDR summaries and citation tracking.
Best for: Finding and skimming papers
SRC-06100% Free
ResearchRabbit
Used for
Maps related papers and authors visually so you can discover research connected to papers you already know.
Best for: Exploring a research field
SRC-07Free plan
Connected Papers
Used for
Builds a visual graph of papers similar to one paper, helping you find prior and later work.
Best for: Finding related studies
SRC-08Free plan
You.com
Used for
AI search and chat that combines web results with assistant answers and research mode.
Best for: Web research with chat