Does ChatGPT Search Use Google, Bing, or Its Own Index?

What has OpenAI said?

OpenAI's statements are brief:

• Launch, 2024: ChatGPT search "leverages third-party search providers, as well as content provided directly by our partners".
• Crawler documentation: OAI-SearchBot is used to surface websites in ChatGPT search. Sites that block it will not be shown in ChatGPT search answers, apart from navigational links, and changes take about 24 hours to apply.
• Live fetching: ChatGPT-User visits pages when a user's request needs them. OpenAI says it is not used for automatic crawling or to decide search eligibility.
• Publisher guidance: any public website can appear in ChatGPT search.
• Launch Q&A, October 2024: OpenAI's engineering VP said ChatGPT search uses "a set of services and Bing is an important one".

OpenAI has not named its search providers in detail. Beyond that, the evidence comes from outside analysis.

What does the outside evidence show?

Taken together, the evidence is mixed: one study found strong Bing overlap and a larger one did not, Google data shows up in some verticals, and OpenAI increasingly uses its own index, covered below. The picture may have shifted since these studies. The Bing Search APIs that developers used were retired in August 2025, so whatever arrangement OpenAI has with Microsoft is private.

Does OpenAI use Bing’s search index and APIs instead of Google?

Not exclusively, and possibly not mainly. OpenAI's engineering VP called Bing "an important one" of several services in 2024, overlap studies disagree, and a 2026 analysis found most results coming from OpenAI's own index and scraping providers. "Instead of Google" also overstates it. The 2025 SerpApi report showed Google results being used for some current-events answers, and shopping results track Google Shopping. OpenAI's own wording, "third-party search providers", is plural. The safest assumption is that ChatGPT combines its own index with several providers, Bing among them.

Does Bing SEO improve your visibility in ChatGPT?

It can help, because Bing is one of ChatGPT's providers, but it is not a prerequisite: OpenAI also crawls pages into its own index and uses other providers. Practical steps:

1. Verify your site in Bing Webmaster Tools and check that important pages are indexed.
2. Submit new and updated pages through Bing's URL submission or IndexNow, which shares submissions with other participating engines.
3. Fix Bing-specific issues shown in its reports, such as crawl errors or blocked resources.
4. Allow OAI-SearchBot in robots.txt and in your CDN or firewall, since blocking it keeps you out of ChatGPT search answers, apart from navigational links, regardless of Bing.

What Bing SEO will not do on its own is make ChatGPT recommend you. ChatGPT writes its own queries, often several per question, reads a handful of results, and chooses what to cite. Pages that answer the question directly, and brands mentioned on the review and comparison sites it reads, still win. For products, keep your Google Merchant Center feed in good shape too. How ChatGPT's queries work is covered in how to use browser tools to reveal ChatGPT's search queries and fan-outs.

Is OpenAI building its own web index?

At least partly. OAI-SearchBot crawls the web to surface sites in ChatGPT search, and blocking it keeps a site out of search answers, apart from navigational links. That means OpenAI keeps its own record of which pages are eligible and, in practice, an index of what it has crawled. ChatGPT's head of product, Nick Turley, testified in Google's antitrust case that OpenAI began building its own search index in 2023. Peec AI's September 2026 analysis of ChatGPT's result sources found most results coming from OpenAI's own index, internally called Labrador, and from providers that scrape Google, with Bing showing up mainly in Deep Research. How much each source contributes for your topics is not public. ChatGPT-User adds live page fetches on top. For site owners, the implication is the same either way: let OpenAI's search crawler in, keep pages fast and readable without JavaScript, and check your logs to see it arriving.

Should you still care about Google for ChatGPT?

Yes, for three reasons. First, shopping answers track Google Shopping data, so a clean Merchant Center feed helps products appear in ChatGPT as well as in Google. Second, for fresh topics such as news, reports suggest Google results have been part of the mix. Third, the pages that do well in Google and Bing are usually the same well-built, clearly written pages, and the sites that cite and review you are found through both.

What changes is the order of work. If you have only ever checked Google Search Console, open Bing Webmaster Tools next. It is the gap most sites have, and one of the few that is quick and free to close. Then look at your server logs for OAI-SearchBot and ChatGPT-User, to confirm OpenAI's own crawlers can reach you.

How can you test what ChatGPT uses for your topics?

1. Pick ten questions your customers ask.
2. Ask ChatGPT with search on, and record the cited URLs.
3. Run the same queries in Bing and Google, or the sub-queries ChatGPT used if you can see them.
4. Count overlaps with each engine's top 20.
5. Check shopping questions separately, comparing products with Google Shopping.

If citations match Bing more, improve your Bing presence first. If they match neither, work on the third-party pages ChatGPT keeps citing. Why different assistants cite different sources is covered in why ChatGPT, Perplexity and Google cite different sources, and the Google ranking question in whether 90% of ChatGPT citations come from pages ranked 21 or lower.

What might this look like in practice?

Consider an illustrative home insurance broker, Hollin & Reed, that ranked well in Google but was rarely cited by ChatGPT. Bing Webmaster Tools showed that half of its guides were not indexed in Bing, and its CDN was challenging OAI-SearchBot. After allowing the bot, submitting its guides through IndexNow and fixing two crawl errors, its guides began appearing among ChatGPT's cited sources for some questions within a month. For questions where ChatGPT kept citing two comparison sites, the broker worked on getting listed there.

What do people ask about ChatGPT's search sources?

Does ChatGPT use Google?

Partly. Reports in 2025 found OpenAI using scraped Google results for some current-events answers, and its shopping results track Google Shopping. Studies disagree on whether ordinary results overlap more with Bing or Google.

Does ChatGPT use Bing?

Probably, among other providers. Overlap studies are mixed: Seer found 87% of ChatGPT search citations in Bing's top 20 for the same question, while a larger Ahrefs study found about 8% overlap with both Bing's and Google's top 10. At launch, OpenAI's engineering VP said it uses "a set of services and Bing is an important one"; OpenAI's documentation only says "third-party search providers".

What happens if I block OAI-SearchBot?

OpenAI says your site will not appear in ChatGPT search answers, except as navigational links.

Is Bing Webmaster Tools worth setting up?

Yes. It is free and quick, and it closes one of ChatGPT's routes to your pages, though Bing is not the only one.