Deep Research : Perplexity, OpenAI, Gemini – Who’s the best?

After searchGPT OpenAI broke new ground with the Deep Research feature, which stands out for its ability to perform deep, exhaustive searches in record time. This functionality has also been integrated into several other AI tools such as Perplexity, Google Gemini and others that promise to transform the way we access and analyze information.

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In brief: Perplexity stands out for its speed cost and accessibility, OpenAI for its depth of analysis, and Gemini for its dynamic interface and advanced visualizations.

What is Deep Research?

It’s an advanced agentic artificial intelligence feature designed to explore, synthesize and present complex information in a structured and understandable way.

It uses sophisticated algorithms to analyze tens, if not hundreds of online sources, and extract the relevant data.

The result is a detailed report that summarizes key information and offers valuable insights.

How Deep Research works

There are several key stages in the process:

1. In-depth Analysis: The tool begins by exploring a wide range of online content, including websites, academic articles, specialist publications and databases. This analysis is exhaustive and covers a variety of fields and topics.
2. Intelligent synthesis: Once the data has been collected, the AI uses natural language processing (NLP) and machine learning techniques to synthesize the information. It identifies key points, trends and main conclusions, and organizes them in a coherent way.
3. Report Generation: AI then builds a structured report that presents the key information clearly and concisely. This report can include tables, graphs and visualizations to aid comprehension.

Benefits of Deep Research

• Speed: Deep Research provides in-depth analysis in minutes, where a human would take several hours.
• Precision: Advanced algorithms guarantee high precision in information extraction and synthesis.
• Accessibility: Generated reports are easy to understand and share, making information accessible to a wide audience.
• Efficiency: By automating the search process, Deep Research frees up time for users, enabling them to concentrate on analysis and decision-making.

Application examples

• Finance: Financial analysts can use Deep Research to obtain detailed reports on market trends, company performance and economic forecasts.
• Marketing: Marketing professionals can analyze consumer behavior, market trends and the effectiveness of advertising campaigns.
• Academic research: Researchers can synthesize hundreds of articles and publications to gain an overview of a specific topic.
• Market analysis: Companies can assess the competition, identify market opportunities and adapt their strategies accordingly.

Comparative: Perplexity vs OpenAI vs Google Gemini

Despite their differences, AI tools like Perplexity, OpenAI and Google Gemini share several common features in their approach to Deep Research:

To help you choose the best AI search tool in 2025, here’s a detailed comparison between Perplexity Deep Research, OpenAI Deep Research and Google Gemini Deep Research.

Key features

Feature	Perplexity Deep Research	OpenAI Deep Research	Google Gemini Deep Research
Launch date	February 2025	February 2025	December 2024
Pricing	Free with 5 queries per day; 20/month for 500 daily queries	$200/month for 100 queries	$20/month (Gemini Advanced)
Processing time	Less than 3 minutes per job	5-30 minutes per query	Generally less than 15 minutes
Precision (Humanity’s Last Exam)	21,1%	Over 21.1%	6.2%
Availability	Web; soon on iOS, Android, Mac	Currently in US, expansion planned	Global via Gemini web app (English only)
Research methodology	Executes multiple searches quickly, basic source analysis	Systematic and in-depth, with detailed research methodology section	Very iterative and dynamic, uses live data extraction, annotations and cross-checks
Depth of analysis	Provides preliminary insights, but lacks comprehensive data on some indicators	Provides in-depth analysis with comprehensive resource review	Offers very in-depth analysis with strategic recommendations and visualizations
Interface and visual features	Simple text report with formatted tables, few interactive visuals	Well-structured report with headers and summary tables, static interface	Dynamic interface with interactive graphics and real-time updates
Support tools and features	Utilizes basic report generation tools, lacks advanced visual tools	Utilizes robust web search and document synthesis tools, full citations	Integrates advanced charting, annotation and real-time source checking tools
Structure and clarity of results	Report organized with clear sections and tables, but lacks some data points	Report clearly organized with explicit figures and detailed citations	Results structured in layers following a logical progression, with direct strategic recommendations
Recommended use case	Ideal for quick preliminary analyses, but less suitable for full market analyses due to incomplete data	Ideal for strategic planning requiring a detailed, static report with a clear methodology	Ideal for decision-makers and analysts requiring a dynamic, transparent and thorough research process, despite longer research time

Advantages and Disadvantages

Perplexity Deep Research

Benefits:

• Accessibility: Free version with 5 queries per day and affordable Pro version.
• Speed: Processing time of less than 3 minutes per job.
• Precision: Good performance on evaluation benchmarks.

Disadvantages:

• Depth of analysis : Sometimes lacks complete data on certain indicators.
• Interface: Lack of interactive visuals.

See the official page : https://www.perplexity.ai/fr/hub/blog/introducing-perplexity-deep-research

OpenAI Deep Research

Benefits:

• Depth of analysis: In-depth analysis with exhaustive review of resources.
• Structure of results: Well-structured reports with explicit figures and detailed citations.

Disadvantages :

• Pricing: High cost at $200/month for 100 queries.
• Processing time: Slower with a processing time of 5 to 30 minutes per request.

See the official page: https://openai.com/index/introducing-deep-research

Read our article on OpenAI Deep Research: Deep Research : the AI agent that performs complex searches in record time

Google Gemini Deep Research

Benefits:

• Dynamic interface : Interactive graphics and real-time updates.
• Depth of analysis: Highly in-depth analysis with strategic recommendations and visualizations.

Disadvantages:

• Accuracy: Accuracy score lower than competitors.
• Processing time: Moderate processing time of less than 15 minutes.

See the official page: https://blog.google/products/gemini/google-gemini-deep-research/

Concluding

Each AI search tool has its own strengths and weaknesses, and the choice will depend on the user’s specific needs:

• Perplexity Deep Research is ideal for quick, accessible analysis, but may lack depth for complex analysis.
• OpenAI Deep Research is the best choice for in-depth, structured analyses, but at a high cost and with a longer processing time.
• Google Gemini Deep Research offers a dynamic interface and in-depth analysis, but with lower accuracy and moderate processing time.