Does ChatGPT use Google or Bing?

When it searches, ChatGPT does not send the question as typed. It breaks it into several narrower searches, a process known as query fan-out. According to an Ahrefs analysis published on 20 August 2025, ChatGPT ran 1.78 searches per prompt on average, and 75% of prompts triggered exactly two.

Those searches are what gets sent to one or more indexes. That is why “Google or Bing?” is a real question: it decides which index a site has to be in for ChatGPT to find it when it searches.

What can be stated today with a source:

• Bing: Microsoft announced on 23 May 2023 that Bing was becoming the default search experience in ChatGPT, and Ahrefs still described it in 2025 as ChatGPT’s built-in provider.
• Its own index: OpenAI’s crawler documentation, checked on 12 November 2026, says OAI-SearchBot is used to surface websites in ChatGPT’s search results.
• Google: on 6 August 2025, Semrush reported two experiments in which ChatGPT cited a page that only Google could have indexed.

What cannot be stated is that ChatGPT “is Google” or “is Bing”. No document from OpenAI or Microsoft gives a split, and the studies that measured citations find no dominant search engine.

The announcement is on Microsoft’s official blog, dated 23 May 2023. It was the first time ChatGPT reached the web through a search engine, and it is why many people still believe ChatGPT only uses Bing.

That belief has aged. In April 2025, at the remedies trial in the United States’ case against Google, ChatGPT’s head of product, Nick Turley, testified that OpenAI is building its own search index but that it will take several years before it can rely on it entirely, according to Tech Policy Press’s report of 29 April 2025.

The first experiment was run by Abhishek Iyer, a former Google engineer: he created a page about a made-up term, let only Google access it and then asked ChatGPT about the term. ChatGPT answered citing his page. Leigh McKenzie, of Backlinko, repeated it with different versions of ChatGPT, and his results suggested that ChatGPT Plus used Google while the free version did not.

Semrush is clear about the limit of these tests: they prove ChatGPT uses Google in some cases, not how often or in which circumstances. They are experiments on one page, not a measurement of all searches.

OpenAI’s documentation, checked on 12 November 2026, puts it plainly: “Sites that are opted out of OAI-SearchBot will not be shown in ChatGPT search answers, though can still appear as navigational links.” OpenAI recommends allowing it in robots.txt, the file a site uses to tell each robot what it may read, and allowing requests from its published IP ranges.

Two details from the same documentation prevent expensive mistakes. A robots.txt change takes about 24 hours to apply to search. And OAI-SearchBot is independent of GPTBot, the training crawler: a site can allow one and block the other.

To find out in two minutes whether both get through, there is the free AI crawler test, which reads robots.txt and checks how the site responds to each agent.

That study is by Louise Linehan, published on 11 August 2025 and updated on 31 May 2026. Its conclusion on ChatGPT is that, in its data, there is little difference in how it surfaces Google and Bing results.

A second Ahrefs analysis, by Si Quan Ong, compared 118,931 ChatGPT fan-out queries with Google’s results for the same queries. Only 6.82% of what ChatGPT chose was in Google’s top 10, and 83.39% did not appear in Google’s results at all. The author concludes that ChatGPT probably blends several sources and applies its own ranking.

Why the question matters shows up in customers. ChatGPT is among the assistants that leads at Kulturo and HeyTalent name most, according to what they say in sales conversations. Why ChatGPT picks some pages over others is covered in how AI models choose their sources.

What to check, in this order:

1. That OAI-SearchBot is not blocked in robots.txt or in the firewall or CDN.
2. That the site is indexed in Google, using Google Search Console.
3. That the site is indexed in Bing, using Bing Webmaster Tools, which many companies have never looked at.
4. That the content is in the page’s HTML and does not appear only after JavaScript runs.

Being in the index is the condition for ChatGPT to find a page, not for it to cite it. What gets a brand into the answer is covered in how to appear in ChatGPT and get your brand recommended.

According to indexnow.org, IndexNow is supported by Microsoft Bing, Naver, Seznam.cz, Yandex and Yep. Google is not on that list, so IndexNow speeds up the Bing route and does not replace Google Search Console.

Bing Webmaster Tools also has its own AI performance report, in public preview since 10 February 2026. According to Bing, it shows a site’s citations in Microsoft Copilot, in AI-generated summaries in Bing and in a selection of partner integrations it does not name. It does not allow anyone to say it includes ChatGPT.

The report is useful even though it does not measure ChatGPT. Kulturo had 11,800 AI citations between late July and October 2026, with an average of 16 cited pages, according to Kulturo’s AI performance report in Bing Webmaster Tools. How to read it is explained in the guide to Bing’s AI Performance report, and the rest of the figures are in the Kulturo case study.

Those logs show which pages each robot visits and when. OAI-SearchBot visits tell you which pages can enter ChatGPT’s search index. ChatGPT-User visits, from the agent that, according to OpenAI, opens a page when someone asks ChatGPT a question, are the closest thing to knowing the assistant has read that page in a conversation.

Neither log says what ChatGPT writes in the answer or whether it names the brand without opening its site; that still takes a fixed set of questions. This is what DoGeo sets up for each client: a log of each assistant’s robots, alongside that set of questions.