How ChatGPT Search Works: OpenAI's 'Searching the Web With ChatGPT' Explained

'Searching the web with ChatGPT' is a help-center article published by OpenAI. It explains, for users and site owners, how ChatGPT's search feature finds and shows web pages.

It is first-party documentation, not a study. OpenAI describes its own system. Nobody outside OpenAI tested the claims, and the article does not report measurements.

That makes it useful for one thing: knowing what OpenAI says the rules are. It pairs with OpenAI's bot documentation, which defines the crawlers the help article refers to. Our digest of OpenAI's crawler documentation covers that page.

99Research read the article as part of a verified evidence base built on 2026-08-22. Every claim we quote was checked against the live page at that date.

Two limits apply to this kind of source:

• No fixed date. The article shows only a relative update time (it read 'Updated: 20 hours ago' when fetched). You can't tell from the page when a sentence changed.
• Hard to monitor. help.openai.com returns a 403 to non-browser clients, so automated change tracking can't read it directly.

So treat everything below as accurate as of our verification, and re-read the article before acting on a detail. As of October 2026, we know of no change to the points below.

Eligibility is a conjunction

The key sentence for site owners: 'To make a website eligible for inclusion, allow OAI-Searchbot to crawl the site and confirm that the website host or content delivery network allows traffic from OpenAI's published searchbot IP addresses.'

The word that matters is 'and'. A robots.txt allow is not enough if your firewall blocks the crawler. OAI-SearchBot is the search crawler. GPTBot is the training crawler, and OpenAI's bots page says 'Each setting is independent of the others.'

Prompts get rewritten

OpenAI states that 'ChatGPT search typically rewrites your query into one or more targeted queries that it sends those providers.' This is query rewriting. The search that runs is not the sentence the user typed.

Other search providers are involved

The article says ChatGPT search 'sometimes partners with other search providers', naming Microsoft. The wording is hedged. It does not say how often, or for which queries.

Memory shapes the rewrite

'If memory is enabled, ChatGPT may use relevant saved memories when rewriting a search query.' For product results, OpenAI says ChatGPT considers 'your query and context (such as Memory or Custom instructions).'

Ranking is undisclosed

OpenAI's full ranking disclosure is: 'ChatGPT ranks search results using multiple factors intended to help users find relevant, reliable information. Placement is not guaranteed.' No factor is named.

The article tells you how to become eligible. It does not tell you how to be chosen.

• Eligibility is not retrieval. Allowing OAI-SearchBot and opening your firewall puts you in the pool. It doesn't make ChatGPT fetch or cite you for any query.
• Search doesn't always run. ChatGPT searches at the model's discretion. Some answers come from the model's training data, with no retrieval at all.
• The real queries are hidden. Because prompts are rewritten, you can't see what was actually searched. Tracking the prompts you chose measures a proxy. See whether AI searches for the exact question.
• No provider share. 'Sometimes partners' gives no frequency. The named-provider language traces to 2024-era documentation, so don't treat Bing presence as a measured route into ChatGPT.
• No ranking factors. 'Multiple factors' rules out any honest claim about what ChatGPT rewards.
• Answer-time fetching is separate. OpenAI's bots page says robots.txt rules 'may not apply' to ChatGPT-User, which acts on a user's request. The help article's eligibility rule is about OAI-SearchBot.

Memory and custom instructions change the rewritten query. So two people asking the same question can trigger different searches and get different sources.

If you test how ChatGPT answers buyer questions, control what you can:

1. Test logged out, or with memory off and custom instructions cleared.
2. Record whether the answer showed citations. No citations usually means you can't tell whether search ran.
3. Repeat each question more than once. One answer is a sample, not a verdict.
4. Compare like with like. A logged-in, memory-on result is not comparable with a clean session.

Say you run a hypothetical accounting firm in Leeds. Your own ChatGPT account, full of saved notes about your firm, is the worst place to check whether strangers see you. A clean session is closer to what a prospect gets.

The help article gives you two gates. Check both, because failing either one is silent.

Gate one: robots.txt

Make sure OAI-SearchBot is not disallowed. A common error is a blanket AI block that removes search eligibility while the owner meant to stop training. To block training but stay in ChatGPT search:

User-agent: GPTBot
Disallow: /

User-agent: OAI-SearchBot
Allow: /

Gate two: host, CDN and firewall

Request a real content URL with the OAI-SearchBot user agent and look at the status code. A 200 passes. A 403, a 429, or a JavaScript challenge page fails. OpenAI's own guidance notes that bot-protection systems 'can mistakenly block legitimate crawlers, often returning 403 Forbidden errors.'

Things to know before you change firewall rules:

• OpenAI publishes its search crawler ranges at openai.com/searchbot.json. When we checked on 2026-08-22, it listed 35 IPv4 prefixes and no IPv6 prefixes. An origin that only answers over IPv6 may be unreachable; see whether ChatGPT's crawlers can reach an IPv6-only site.
• OpenAI also warns against IP-only allowlisting. Read whether to allowlist OpenAI's crawler IPs before you hard-code ranges.
• From 2026-09-15, Cloudflare blocks Training and Agent crawler categories by default on ad-displaying pages for new domains and existing free-tier customers, with Search left allowed. Recheck if you're on Cloudflare.

Our page on OpenAI crawlers, robots.txt and firewalls walks through both gates. The AI Crawler Checker requests a page as each AI crawler and shows which ones your firewall turns away.

Passing both gates makes you eligible. What ChatGPT does next is outside your control.