Does ChatGPT use Bing’s index?

The short answer

For years the standard advice was “ChatGPT search is Bing, so get into Bing”. In October 2026 that is too simple. Here is what the sources say, strongest first:

• OpenAI: “ChatGPT search sometimes partners with other search providers”, rewriting your question into queries it sends them. The page links Microsoft’s and Shopify’s privacy policies and doesn’t name a search index. To make a site eligible, OpenAI asks you to let OAI-SearchBot crawl it and to let its published IP addresses through your host or CDN (OpenAI Help, Searching the web with ChatGPT, read 15 Oct 2026).
• OpenAI’s crawler page: sites that opt out of OAI-SearchBot “will not be shown in ChatGPT search answers”, and robots.txt changes take about 24 hours to apply (OpenAI crawlers, read 15 Oct 2026).
• Microsoft: Bing and Copilot search experiences “rely on the same core crawling, indexing, and ranking foundation as traditional search” (Bing Webmaster Guidelines, read 15 Oct 2026).
• A third-party analysis: Peec AI reviewed ChatGPT’s response events between May and July 2026 and reports a result_source field with four values: OpenAI’s own index and three outside providers. It saw Bing mainly in Deep Research sessions (Peec AI, 4 Sep 2026; vendor analysis, inferred from outside OpenAI).

So: ChatGPT reads your site with its own crawler and may also pull from partners; Copilot is Bing. Be in both, for different reasons.

Which index feeds which assistant

What our own data says

Our sample site got its first ChatGPT visitor about a day and a half after launch. On 24 September 2026 Bing had indexed 0 of its pages, and ChatGPT still sent it 40 visitors that day (own measurement). In its first 7 days ChatGPT sent 333 visitors, 63% of human traffic (source: the site’s own analytics, human sessions only, 528 of 1,546, 21 to 27 September 2026; one sample site, our own product; details in the case study). That fits OpenAI’s description: being crawlable by OAI-SearchBot mattered, and a Bing listing wasn’t needed for it. It’s one site, not a rule.

How to get a new site into Bing

1. Verify the site in Bing Webmaster Tools.
2. Submit one sitemap that lists only canonical, live URLs. Bing asks you to remove deleted or redirected URLs promptly and to keep lastmod accurate.
3. Set up IndexNow: host a key file and send each added, changed or removed URL. Bing’s guidelines say to notify it when URLs are added, updated or removed.
4. Check Bingbot isn’t blocked in robots.txt or by your CDN. The AI crawler checker tests the AI bots; for Bingbot, use Bing’s own URL Inspection.
5. Put the text in the HTML. Bing lists “hiding critical content behind client-side rendering” among the things to avoid. The fix for single-page apps is on six traps for vibe-coded sites.
6. Use 301s for moved pages and 404 for deleted ones, as Bing asks. If Google also shows old URLs, see Crawled, currently not indexed.
7. Watch the AI Performance report for Copilot citations once pages are indexed (Bing, 10 Feb 2026).

Example: one IndexNow request

curl -si -X POST "https://api.indexnow.org/indexnow" \
  -H "Content-Type: application/json; charset=utf-8" \
  --data '{"host":"yoursite.com","key":"YOUR_KEY","urlList":["https://yoursite.com/new-page"]}' | head -1

The key file must sit at https://yoursite.com/YOUR_KEY.txt and contain the key. A 200 or 202 means the request was received, not that the page is indexed; 403 means the key file wasn’t found (IndexNow documentation, read 15 Oct 2026). Send only new or changed URLs, not your whole sitemap every day.

What Katman does here

Katman is an MCP server that runs inside your AI coding tool. katman_audit_site checks that OAI-SearchBot, ChatGPT-User and the other AI bots get a 200 through your CDN, and that your pages carry their text without JavaScript. katman_indexnow sets up and verifies your key file, sends only new or changed URLs, and returns the manual checklist for Search Console, Bing Webmaster Tools and Brave. Katman Pro is $99 a month for up to 3 sites, with fix prompts and page briefs uncapped. Or have us do it: Growth writes 30 pages a month for you.

It can’t log in to Bing Webmaster Tools for you, it doesn’t know OpenAI’s source mix any better than OpenAI says, and nobody can promise an assistant will recommend you. To see whether the work shows up in answers, see how to track brand mentions in AI answers.

Written by the Katman team, Rnify Limited. OpenAI, Microsoft Bing, IndexNow and Peec AI pages checked 15 October 2026.