Perplexity
Perplexity
AI-powered research and answer engine focused on web-grounded responses with citations.
Research & Knowledge
Search, read and synthesise sources, papers and your own documents.
Tools in Research & Knowledge
11 tools
View details
NotebookLM
Google's source-grounded AI research and learning workspace built around user-provided sources.
Gemini
Google's multimodal AI assistant for writing, planning, research, and Google-connected workflows.
Elicit
Elicit
Academic research assistant for literature search, evidence extraction, and systematic review workflows.
SciSpace
SciSpace
AI research platform for understanding papers, literature discovery, and evidence-focused academic workflows.
ChatGPT
OpenAI
General-purpose AI assistant for writing, research, coding, image, voice, and everyday productivity.
Grok
xAI
xAI's general-purpose AI assistant for reasoning, research, multimodal interaction, and real-time information.
Consensus
Consensus
AI academic search platform for question-driven evidence discovery and research synthesis.
Julius AI
Julius AI
AI data analysis workspace for exploring, cleaning, visualizing, and statistically analyzing data with natural language.
Microsoft Copilot
Microsoft
Microsoft's general AI companion for web-assisted answers, writing, productivity, and creative tasks.
Claude
Anthropic
AI assistant focused on writing, analysis, research, coding, and knowledge-intensive work.
Choosing Research & Knowledge tools
Research and knowledge tools search the web or academic sources, read papers and documents, and pull out answers with references. Others organise your own notes and files so you can ask questions of them.
For research, the most important feature is being able to check the answer. Prefer tools that show their sources clearly and make it easy to open them. For your own documents, look at which file types are supported and how private your material stays.
Always open the cited sources for anything that matters. AI summaries can miss nuance, merge findings from different studies or cite a source that does not say what the summary claims. Use these tools to find and triage material faster, then read the key sources yourself.
Who it is for
Students, researchers, analysts and anyone who needs reliable answers from many sources or from a large set of their own documents.
What to compare
- Clear citations and links to original sources
- Coverage: the open web, academic papers, or your own files
- File types and document sizes supported
- Privacy of uploaded documents
- Export options and free plan limits
Common uses
- Finding and summarising academic papers
- Answering questions with cited sources
- Searching your own notes and documents
- Preparing literature reviews and briefings
On ToolIndexHub, each listing shows the pricing model, free plan, platforms and API access that we have recorded, and when an editor last checked them. Where a fact has not been checked yet, the page says so rather than guessing.