# Deep research

Category: [AI Search & GEO](https://seo-geo-glossary.com/en/glossary/category/ai-search-geo/) › [AI search & answer engines](https://seo-geo-glossary.com/en/glossary/category/ai-search-geo/ai-search-answer-engines/)

**Deep research** is a feature of AI assistants that investigates a topic across many web sources in several steps and returns a longer report with source links. It belongs to the agentic AI applications.

## How does deep research work?

Google's Gemini page describes four steps. The system turns a question into a multi-step research plan, searches the web automatically, shows its reasoning while it examines findings, and then writes a multi-page report. Gemini can also use a user's own files such as Gmail or Drive content and uploaded documents. Google introduced the feature in Gemini on December 11, 2024. OpenAI introduced deep research in ChatGPT on February 2, 2025, starting with Pro users. According to reports, Perplexity offers a comparable feature under the same name.

Each product runs its own process. What they share is the pattern of planning, repeated searching and reading, and a final report with citations.

## What does it mean for SEO?

A deep research run reads far more pages than a single AI answer and lists them as sources. Only content that the system can fetch and read can be used (assessment). Reports can contain citations and links that bring visitors, which relates to AI citations. Whether a given fetch follows robots.txt depends on the provider and the bot involved.

## Example

A buyer asks for a comparison of enterprise crawlers for websites with several million URLs. The system forms subquestions about prices, features and reviews, opens vendor pages and review sites, and after some minutes returns a multi-page comparison with footnotes. Which pages appear as sources is decided by the system.

## Common questions

**How does deep research differ from a normal AI answer?**
A normal answer is generated in one pass. Deep research works in multiple steps and returns a longer report with sources.

**Are the results reliable?**
An automatically generated report can contain mistakes and wrong conclusions (assessment), so readers should check the cited sources themselves.

*Diagram: Query fan-out.* A page can appear in the answer because it answers one sub-question well, without ranking for the original question (an inference from the method, not a Google statement).

## AI search: from ChatGPT to AI Mode

- **November 30, 2022:** OpenAI releases ChatGPT as a free research preview. The model is based on the GPT-3.5 series. ([Source](https://openai.com/index/chatgpt/))
- **February 6, 2023:** Google announces its conversational AI service Bard and opens it to trusted testers first. ([Source](https://blog.google/technology/ai/bard-google-ai-search-updates/))
- **February 7, 2023:** Microsoft launches the new Bing with AI chat and complete answers inside search. ([Source](https://blogs.microsoft.com/blog/2023/02/07/reinventing-search-with-a-new-ai-powered-microsoft-bing-and-edge-your-copilot-for-the-web/))
- **May 10, 2023:** Google introduces the Search Generative Experience (SGE) as an experiment in Search Labs. At launch it is limited to the US and English. ([Source](https://blog.google/products/search/generative-ai-search/))
- **November 15, 2023:** Microsoft renames Bing Chat to Copilot. General availability follows from December 1, 2023. ([Source](https://blogs.microsoft.com/blog/2023/11/15/microsoft-ignite-2023-ai-transformation-and-the-technology-driving-change/))
- **May 14, 2024:** At Google I/O, Google announces AI Overviews for everyone in the US, with more countries to follow. ([Source](https://blog.google/products/search/generative-ai-google-search-may-2024/))
- **July 24, 2024:** Bing previews its generative search experience. At first it appears for a small share of queries only. ([Source](https://blogs.bing.com/search/July-2024/generativesearch))
- **July 25, 2024:** OpenAI tests SearchGPT as a temporary prototype with a small group of users and publishers. ([Source](https://openai.com/index/searchgpt-prototype/))
- **October 28, 2024:** AI Overviews roll out in more than 100 countries and territories. Google expects more than 1 billion monthly users. ([Source](https://blog.google/products/search/ai-overviews-search-october-2024/))
- **October 31, 2024:** OpenAI launches ChatGPT search, first for paying users and the SearchGPT waitlist. Answers link to their sources. ([Source](https://openai.com/index/introducing-chatgpt-search/))
- **December 11, 2024:** Google launches Deep Research in Gemini Advanced. It browses the web on its own and compiles a report. ([Source](https://blog.google/products/gemini/google-gemini-deep-research/))
- **December 16, 2024:** ChatGPT search becomes available to all logged-in users in regions where ChatGPT is offered. ([Source](https://openai.com/index/introducing-chatgpt-search/))
- **February 2, 2025:** OpenAI introduces deep research in ChatGPT, starting with Pro users. ([Source](https://openai.com/index/introducing-deep-research/))
- **February 5, 2025:** ChatGPT search becomes available without signing up in all regions where ChatGPT is offered. ([Source](https://openai.com/index/introducing-chatgpt-search/))
- **March 5, 2025:** Google introduces AI Mode as an experiment in Search Labs. Google One AI Premium subscribers get access first. ([Source](https://blog.google/products/search/ai-mode-search/))
- **March 20, 2025:** Anthropic adds web search with citations to Claude. It launches as a preview for paid users in the US. ([Source](https://www.anthropic.com/news/web-search))
- **March 26, 2025:** AI Overviews launch in Germany in German and English, together with other European countries. They are shown to signed-in users aged 18 and over. ([Source](https://blog.google/intl/de-de/produkte/suchen-entdecken/uebersicht-mit-ki-start/))
- **May 20, 2025:** At Google I/O, Google rolls out AI Mode to everyone in the US, with no Labs sign-up needed. ([Source](https://blog.google/products/search/google-search-ai-mode-update/))
- **May 20, 2025:** AI Overviews are available in more than 200 countries and territories and in more than 40 languages. ([Source](https://blog.google/products/search/ai-overview-expansion-may-2025-update/))
- **May 27, 2025:** Web search in Claude becomes available globally on all plans. ([Source](https://www.anthropic.com/news/web-search))
- **June 16, 2025:** Data from AI Mode counts towards the totals in the Search Console Performance report. ([Source](https://developers.google.com/search/updates#ai-mode-is-now-counting-towards-totals-in-search-console))
- **October 8, 2025:** AI Mode launches in Germany, Austria and Switzerland as part of an expansion to more than 40 new countries and territories. ([Source](https://blog.google/intl/de-de/produkte/suchen-entdecken/ki-modus-startet-in-dach/))
- **June 3, 2026:** Search Console adds dedicated performance reports for generative AI features such as AI Overviews and AI Mode, first for a subset of sites. ([Source](https://developers.google.com/search/blog/2026/06/gen-ai-performance-reports))
- **August 31, 2026:** The Search Console reports on generative AI features become available to all websites worldwide. ([Source](https://developers.google.com/search/blog/2026/06/gen-ai-performance-reports))

## Related terms

- [Agentic search](https://seo-geo-glossary.com/en/glossary/agentic-search/index.md)
- [AI agent](https://seo-geo-glossary.com/en/glossary/ai-agent/index.md)
- [Query fan-out](https://seo-geo-glossary.com/en/glossary/query-fan-out/index.md)
- [AI citation](https://seo-geo-glossary.com/en/glossary/ai-citation/index.md)
- [AI search](https://seo-geo-glossary.com/en/glossary/ai-search/index.md)

## Sources

- [Gemini Deep Research – Google Gemini](https://gemini.google/overview/deep-research/)
- [Try Deep Research and our new experimental model in Gemini – Google Blog (Dec 11, 2024)](https://blog.google/products/gemini/google-gemini-deep-research/)
- [Introducing deep research – OpenAI (February 2, 2025)](https://openai.com/index/introducing-deep-research/)

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Last updated: October 8, 2026
URL: https://seo-geo-glossary.com/en/glossary/deep-research/