Definition
ChatGPT Search is the web search capability built into ChatGPT. When a question needs current or external information, ChatGPT rewrites it into one or more search queries, reads the results and writes an answer with inline citations and a Sources panel. OpenAI launched it in October 2024, and its help center now lists web search on every plan, including for people who are not signed in.
ChatGPT decides on its own when to search, and users can also start a search manually from the tools menu. OpenAI's help article on searching the web with ChatGPT gives an example of the rewriting step: a question about CCR8 cancer drugs first becomes the query 'CCR8 immunotherapy drug development 2025', and after reading those results ChatGPT may send narrower follow-up queries to other providers. This decomposition is the query fan-out pattern, and it means a page competes on many sub-queries, not on the user's original wording. The same article names Microsoft and Shopify among the third-party search providers, and OpenAI separately documents an 'offline web search' mode for some regulated workspaces that answers only from OpenAI's own index and cache.
Search results are shaped by context. ChatGPT may use approximate location from the user's IP address, saved memories and the conversation so far when it writes queries. Answers can include maps, product results from Shopping with ChatGPT Search, and restaurant availability from OpenTable, Resy or Yelp. With GPT-6, the Chat default since October 7, 2026, OpenAI says the model is better at deciding when to search and starts answering web-search questions 44% sooner on average than GPT-5.6 Instant.
Inclusion depends on crawler access. According to OpenAI's crawler documentation, sites that block OAI-SearchBot are not shown in ChatGPT search answers (they can still appear as plain navigational links), robots.txt changes take about 24 hours to apply, and hosts or CDNs must allow OpenAI's published IP ranges. GPTBot, the training crawler, is controlled separately, and ChatGPT-User fetches pages on demand when a user's question needs them. The differences are covered in citation crawlers vs training crawlers.
Citation behavior is measurable and it moves. ChatGPT typically cites around five sources per web-search answer, which makes each slot scarce. Promptwatch publishes the top ChatGPT citation sources by domain, and its fan-out data shows that on August 8, 2026 ChatGPT began using the site: operator at scale, with site-restricted queries jumping from about 0.4% to about 17% of all fan-out queries overnight. Shifts like this change which domains get pulled in, independent of any change to your content (see site operator queries).
For GEO teams, optimizing for ChatGPT Search comes down to four things: keep OAI-SearchBot and ChatGPT-User unblocked, write pages as self-contained passages that answer one sub-question each (content atomization), keep important pages current, and earn coverage on the third-party sites ChatGPT already cites in your category. Measure it with a fixed prompt set run on a schedule, tracking whether your brand is mentioned, whether your domain is cited, and your citation share against competitors.
Examples of ChatGPT Search
- A user asks 'best project management tool for a 40-person design studio' and ChatGPT runs separate searches for pricing, design-team reviews and Figma integrations, then cites five pages, two of them vendor sites and three review roundups.
- A SaaS brand tracks 120 category prompts and finds its domain is cited in 22% of ChatGPT Search answers but only 8% of Perplexity answers, so it focuses the next quarter on the review sites Perplexity favors.
- A publisher sees a jump in ChatGPT-User requests to its archive pages in August 2026 and links it to ChatGPT's new habit of running site: queries against domains it already trusts.
- A hotel group adds clear opening hours, cancellation terms and neighborhood names to each property page after noticing ChatGPT rewrites 'hotels near me' prompts into city and neighborhood queries.
- A security vendor finds its docs never appear in ChatGPT answers, checks its robots.txt, and discovers a blanket rule meant for GPTBot was also blocking OAI-SearchBot.
