OpenAI says ChatGPT search sends queries to third-party search providers, and one of its own help pages names Bing as an example. It doesn't say how much each provider contributes. Being in Bing's index is still the part of AI search you can check yourself, and most service sites never have.
Does ChatGPT use Bing to search the web?
Partly, as far as anyone outside OpenAI can confirm. OpenAI's help article on ChatGPT search says it rewrites your question and sends it to "third-party search providers", and it links to Microsoft's privacy statement as one of them. A separate OpenAI page, on accounts that handle health data, is more direct: in that setup ChatGPT "does not send queries to third-party search providers (e.g., Bing)" and uses OpenAI's own index instead.
So Bing is in the mix for regular accounts, and it isn't the only source. OpenAI also runs its own crawler for search, called OAI-SearchBot, which it describes as the one used to surface websites in ChatGPT's search results.
What do we actually know about where ChatGPT gets its sources?
Less than most articles on this topic claim. Here is what is documented and what isn't, as of 12 October 2026:
| Claim | Status | Where it's written |
|---|---|---|
| ChatGPT search sends queries to third-party search providers | Documented | OpenAI help, ChatGPT search |
| Bing is one of those providers | Documented as an example | OpenAI help, HIPAA-eligible products |
| OpenAI has its own search crawler, OAI-SearchBot | Documented | OpenAI developer docs, bots |
| GPTBot crawls for model training, not for search | Documented | OpenAI developer docs, bots |
| How much of an answer comes from Bing versus OpenAI's own index | Not documented | Nowhere I could find |
| Ranking well in Bing makes ChatGPT cite you | Not documented | A common assumption, not a published fact |
The practical reading is simple. If you block OAI-SearchBot, or if Bing doesn't have your pages, you are removing yourself from at least one of the routes ChatGPT uses. Neither guarantees a citation. Both are cheap to rule out.
It's also worth knowing that Microsoft retired its public Bing Search APIs in August 2025 and now offers search to AI developers through a product called Grounding with Bing. That is a Microsoft product for developers; it says nothing on its own about any specific deal with OpenAI, and I wouldn't read more into it.
How many service sites are verified in Bing Webmaster Tools?
Very few, as far as the pages themselves show. In September I read the home page and up to three other pages of 343 small professional websites: 54 therapy practices in the United States and 289 Spanish-language sites of therapists, lawyers, accountants, clinics and small businesses. I looked for the tag Bing asks you to add to verify ownership:
| Set | Sites | Without the Bing verification tag |
|---|---|---|
| US therapy practices | 54 | 50 (92.6%) |
| Spanish-language professional sites | 289 | 276 (95.5%) |
| All sites in the study | 343 | 326 (95.0%) |
That is a lower bound. Bing also lets you verify by DNS record, by uploading a file or by importing from Google Search Console, and none of those leave a trace in the HTML. Some of those sites are surely verified another way. Even so, the pattern matches what I see with clients: almost nobody has opened Bing Webmaster Tools, so almost nobody knows whether Bing can see them.
What does Bing's AI performance report show?
Bing added an AI Performance report to Webmaster Tools in February 2026, still marked as beta. It counts how often your pages were cited in Microsoft Copilot, in the AI summaries on Bing and in some partner products, and it shows the queries that led to those citations. Microsoft is clear that a citation is not a click, and its announcement doesn't name ChatGPT among the partners, so don't read the report as a ChatGPT dashboard.
Here is what it showed for this site when I opened it on 12 October, alongside the rest of our Bing data:
| Bing Webmaster Tools, contento.solutions | Value |
|---|---|
| AI citations, 18 September to 10 October | 0 |
| Search impressions in the same period | 17 |
| Search clicks in the same period | 1 |
| URLs sent through IndexNow since 17 September | 116 |
| Pages listed as indexed in Site Explorer | 8 |
| Articles indexed, out of 6 I inspected one by one | 2 |
| Articles discovered but not selected for the index | 4 of the same 6 |
The last two rows are the uncomfortable ones. Google has most of our articles. Bing has found all of them and kept only some: in the six I checked, two were indexed and four were "discovered but not selected", which is Bing's way of saying it knows the page exists and decided not to include it yet. Our services page is in that second group too. If ChatGPT leans on Bing for a question we answer, it often can't find our answer there today. Being verified didn't fix that, and neither did IndexNow. What verification did was let me see it, which is the reason to do it.
Is IndexNow worth setting up on a small site?
Yes, if your platform does it for you or it takes you ten minutes. IndexNow is a shared way to tell search engines a page is new or changed. Bing, Yandex, Naver, Seznam and Yep take part; Google doesn't appear on the list. It speeds up discovery. It doesn't promise indexing, and our 116 submitted URLs against a handful of indexed pages show the difference.
The order I'd follow on a small site: verify in Bing Webmaster Tools (importing from Search Console takes a few minutes), submit the sitemap, check that robots.txt doesn't block Bingbot or OAI-SearchBot, and only then set up IndexNow. After that, look at Site Explorer once a month to see which sections Bing actually keeps. More on making pages worth citing once they're found in how to make your website citable in AI search, and on why ranking in Google isn't enough in ranking first on Google and still being invisible to AI.
Questions I get about this
If I block GPTBot, will I disappear from ChatGPT search?
Not according to OpenAI. GPTBot is the training crawler. Search uses OAI-SearchBot, and you can allow one and block the other.
Does Bing Webmaster Tools cost anything?
No. It is free, like Search Console.
Does Google use IndexNow?
It isn't listed among the participating search engines. For Google, the sitemap and Search Console are still the way to go.
What I can and can't claim
The OpenAI and Microsoft statements come from their own help pages, developer documentation and announcements, read on 12 October 2026; this relationship changes, so check the date before you rely on it. The verification count comes from the HTML of up to four pages on each of 343 professional websites, read on 17 September 2026, 54 of them US therapy practices; it only sees the meta tag, so it undercounts verified sites. The Bing numbers are from this site's own Webmaster Tools account, a young site with few links. I can't tell you how ChatGPT picks which source to cite, because OpenAI doesn't publish it, and anyone who says otherwise is guessing.
If you want me to check how Bing and the AI crawlers see your site, that is part of the audit, or you can book a strategic fit call and we'll look at it together. For sites in health care, the specifics are in how AI tools can and can't read therapy websites.
