Directory / Research

Research and knowledge

Answer questions from live sources instead of a guess from memory.

5 tools · demo video for each

Perplexity by Perplexity AI

Free tierBeginnerfrom $17/mo billed annually

AI research search that answers questions with inline citations.

What is Perplexity Computer?Perplexity

Best for: Researchers and professionals who want source-backed answers across topics.
Skip it if: You need business-use plans, or conclusions you can rely on without checking.
Cost: Free tier. Pro is about $17/month billed annually, Max $167.
Runs on: Web

Strengths

Inline citations you can open
Deep research on paid plans
Choose among top models on Pro
Builds apps, tools and documents

Watch out for

Pro is priced as an annual equivalent
Free-tier limits are not published in detail
Cited answers still need checking

Visit Perplexity Official pricing

NotebookLM by Google

Free tierBeginnerfrom $4.99/mo

Source-grounded research assistant for exploring and transforming documents.

Introducing NotebookLM Video OverviewsGoogle

Best for: Students, researchers and teams who need grounded synthesis from their own documents.
Skip it if: You need uncapped sources, or a general assistant without a research workflow.
Cost: From $4.99/mo on a Google AI plan; the vendor page does not list a standalone price.
Runs on: Web · Mobile

Strengths

Answers grounded in your sources
Source discovery and deep research
Audio overviews and flashcards
Slides, infographics and video overviews

Watch out for

Source caps run from 50 to 600 per notebook
Paid Google AI plans are region-limited
Works only from the sources you add

Visit NotebookLM Official pricing

Deep Research by OpenAI

In ChatGPTIntermediateIncluded with paid ChatGPT plans

An AI agent that researches complex questions and produces sourced reports.

Introduction to Deep ResearchOpenAI

Best for: Analysts and professionals who need a sourced overview of a complex topic.
Skip it if: You need guaranteed real-time accuracy, or a quick answer to a simple question.
Cost: Included with ChatGPT plans; access depends on the plan you have.
Runs on: Web · iOS · Android

Strengths

Multi-step web research
Reports with linked sources
Synthesis across many sources
Accepts uploaded files

Watch out for

Reports take longer than a chat reply
Citations still need checking
Usage limits follow your ChatGPT plan

Visit Deep Research Official pricing

Elicit

Free tierIntermediatefrom $49/user/mo billed annually

A research tool for finding, summarising and reviewing academic papers.

Automate your systematic review with ElicitElicit

Best for: Researchers and review teams screening literature and extracting findings.
Skip it if: You need unrestricted Research Agent use without paying.
Cost: Free Basic plan. Pro from $49 per user monthly billed annually. Enterprise custom.
Runs on: Web

Strengths

Search across 138 million papers
Summaries and chat with papers
Systematic review screening
Data extraction tables and reports

Watch out for

Basic limits agent and report usage
Pro and Scale prices need annual billing
Enterprise pricing is custom

Visit Elicit Official pricing

Consensus

Free tierIntermediatefrom $12/mo

AI research search and literature review tool.

Consensus AI review and tutorialKingy AI

Best for: Researchers, students and clinicians searching peer-reviewed studies.
Skip it if: You mainly want help drafting a paper rather than finding and reading research.
Cost: Free tier. Pro $12/month, Deep $45/month. Annual billing available.
Runs on: Web · API · MCP

Strengths

Paper search and analysis
Cited answers from studies
Literature reviews across papers
Citation graph and API access

Watch out for

Free tier gives 10 Pro messages a month
Deep reviews are capped by plan
API use beyond the allowance costs extra

Visit Consensus Official pricing

Price watch

Research prices checked 26 October 2026
Tool	Price now
NotebookLM	$4.99/mo
Consensus	$12/mo
Perplexity	$17/mo billed annually
Deep Research	Included with paid ChatGPT plans
Elicit	$49/user/mo billed annually