AI search is search that answers a question with a written response, instead of only a list of links. ChatGPT search, Perplexity, Google's AI Overviews and AI Mode all work this way: they find pages, read them, write an answer, and show some of the pages as sources. Your goal is to be one of those sources.
How is AI search different from regular search?
A classic search engine returns ten or so ranked links and leaves the reading to you. An AI search system does part of the reading. It turns your question into one or more searches, gathers pages, and composes a response with links back to where the information came from.
That changes what success looks like. In classic search you want a high ranking and a click. In AI search you want to be cited inside the answer, and a reader may act on that answer without visiting you at all. Our guide to zero-click search covers that trade-off.
What are the main AI search products?
- Google AI Overviews. A generated summary that appears above some regular results. Google says these appear only when its systems decide they add value beyond classic Search, so many queries never trigger one.
- Google AI Mode. A search experience for complex questions, comparisons and multi-step exploration.
- ChatGPT search. ChatGPT answering with information from the web and linking to sources.
- Perplexity. An answer engine built around cited responses.
The first two come from Google's documentation on AI features. These products use different models and techniques, so the sources shown for the same question can differ from one to the next.
How does AI search pick its sources?
Nobody outside these companies knows every signal, so be wary of anyone who claims a secret formula. What the documentation does say is useful:
- The page must be reachable. A crawler that cannot fetch your page cannot use it. Google says to allow crawling in robots.txt and in any CDN or hosting settings.
- The page must be indexed and eligible for a snippet. Google states that this is the requirement to appear as a supporting link in AI Overviews and AI Mode, with no additional technical requirements.
- The content must answer the question. The system is trying to write an answer, so it needs pages with clear, extractable statements.
Google also describes a technique called query fan-out: while building a response, the system may run several related searches across subtopics and data sources. In practice, a page can be pulled in for a sub-question the user never typed. That rewards pages that cover a topic and its follow-up questions thoroughly, not just the headline phrase.
Which crawlers are involved?
AI products fetch pages with their own bots, and the bots serve different purposes. OpenAI documents three in its bots documentation:
| Crawler | Purpose |
|---|---|
| OAI-SearchBot | Surfaces sites in ChatGPT search |
| GPTBot | Collects content that may be used for training models |
| ChatGPT-User | Fetches a page when a person asks ChatGPT to |
OpenAI says these settings are independent, so a site can appear in ChatGPT search while opting out of training. Blocking the wrong one is a common way to disappear from AI answers by accident. See what an AI crawler is and how to allow ChatGPT and Perplexity in robots.txt.
Is AI search replacing Google?
The evidence in the documentation points the other way for now: Google's AI features sit inside Search, and the same fundamentals apply. Google says there are no additional requirements to appear in AI Overviews or AI Mode, and that no special files, markup or schema are needed. Treat AI search as an additional place your pages can be read, not a separate discipline that makes SEO obsolete.
What should you do about it?
Do these in order, because each step depends on the one before:
- Check access. Read your robots.txt for rules that block search crawlers, including AI ones. If your file is unfamiliar, start with what a robots.txt file should look like.
- Confirm indexing. Pages that Google has not indexed cannot be used as AI Overview sources. Use the checks in how to check if a page is indexed.
- Lead with the answer. Put a direct two or three sentence answer under each question-style heading.
- Cover follow-ups. Because of query fan-out, add sections for the obvious next questions.
- Keep text as text. Google advises keeping important content in text form and structured data consistent with what is visible on the page.
- Measure. Google says AI feature traffic is included in the Search Console Performance report under the Web search type. For citations in other products, see how to track AI citations.
The full prioritized version is in how to optimize for AI search, and the terminology (AEO and GEO) is untangled in what is answer engine optimization.
What does AI search not change?
It does not remove the need for pages that are accurate, specific and sourced. A system that writes answers from web pages is only as good as the pages it finds, which makes clear primary-source writing more valuable, not less. It also does not make shortcuts like stuffing a page with phrases more effective. If anything, an answer engine trying to quote you needs a sentence worth quoting.
Nightcrop's audit includes a check that AI crawlers can reach your site, and its reports track whether AI answer engines cite your domain.
Frequently Asked Questions
What is AI search in simple terms?
Search that replies with a written answer built from web pages, usually with links to the sources it used. Examples include AI Overviews, AI Mode, ChatGPT search and Perplexity.
Is AI search the same as a chatbot?
Not exactly. A chatbot can answer from what it learned in training. AI search looks up current pages and cites them, which is what makes your content eligible to be a source.
Do I need special markup for AI search?
Google says no special files, AI-specific text files or schema.org markup are needed for its AI features. Make sure pages are crawlable, indexed and snippet-eligible.
Can I appear in ChatGPT search but opt out of training?
Yes. OpenAI says its crawler settings are independent, so you can allow OAI-SearchBot and disallow GPTBot.
Will AI search reduce my traffic?
It can, when an answer satisfies the reader without a click. Being cited keeps your name in front of them, and you can measure the effect in Search Console and your analytics.