Why ChatGPT citations come from Bing, not Google

ChatGPT's web search runs on Bing's index, and 87% of ChatGPT brand citations align with Bing's top organic results, per a Seer Interactive study of SearchGPT citation behavior. BrandCited is an AI visibility intelligence platform that monitors brand citations across 9 AI platforms and checks Bing indexing status as a core audit signal. If you haven't optimized for Bing, ChatGPT can't recommend your brand.

GPT-5.5 launched on April 23, 2026. ChatGPT now has 900 million weekly active users, and 36% of those users report discovering new brands through ChatGPT recommendations. That's real brand discovery traffic flowing through a pipeline most marketing teams have never touched. The index that controls it is Bing's, not Google's.

What the Seer Interactive study found#

Seer Interactive ran identical queries through SearchGPT and Bing, then compared which pages each cited. 87% of the pages ChatGPT cited matched pages ranking in Bing's top results for the same query. Most of those matched citations sat in Bing's top 10.

The finding reflects the underlying infrastructure. ChatGPT agents rely on Bing's Search API 92% of the time when retrieving web content to support an answer.

A brand that ranks in Bing's top 5 for a relevant query gets into ChatGPT's citation pool. A brand that doesn't rank on Bing doesn't appear in that pool, regardless of its Google position.

The same study showed that ChatGPT mentions brands 3.2x more than it cites them. Appearing in a ChatGPT answer without a citation still drives brand awareness. Disappearing from Bing means disappearing from both.

Why ChatGPT uses Bing's index, not Google's#

OpenAI's search functionality runs on Microsoft's infrastructure. The OpenAI-Microsoft partnership, announced in 2023 and extended through 2026, includes Bing as the underlying search index for ChatGPT's real-time web access. When ChatGPT needs current information beyond its training data, it queries Bing's API.

Google has not licensed its search index to OpenAI. The two companies compete in AI. ChatGPT Plus uses Bing. Microsoft Copilot uses Bing. Any tool built on the OpenAI API with web search capability uses Bing.

Google AI Overviews work on a different model. They pull from Google's own index. A page that earns Google AI Overview citations does not appear in ChatGPT's citation pool without separate Bing optimization, and a page indexed on Bing but not ranking on Google can still earn ChatGPT citations.

These are two separate indexes, two separate optimization paths, and two separate sets of technical requirements.

What this means for your brand's ChatGPT visibility#

Most brands have spent years optimizing for Google. Bing has pulled around 3-4% of traditional search traffic and was treated as a secondary channel. The assumption was simple: Google ranking equals search presence.

That assumption breaks in AI search. ChatGPT records 5.72 billion monthly visits as of 2026. It drives real brand discovery. Those discovery moments flow to brands that Bing indexes and ranks.

According to the 2026 Search Intelligence Report, Bing's index has grown into an AI-era infrastructure layer powering not just ChatGPT but also Copilot, Yahoo, DuckDuckGo, and Inflection.ai. A site not optimized for Bing is now invisible across a wider range of discovery surfaces than most marketers realize.

There's also a shift in how GPT-5.5 searches. A Writesonic study of 1,821 fan-out queries found that GPT-5.4 used Google's site: operator on 40.5% of its searches, while GPT-5.5 dropped that to 12.6%. The model now relies more on Bing-indexed third-party content and less on domain-scoped Google searches. That shift makes Bing indexing more critical for ChatGPT citation rates, not less.

The Bing indexing gap most brands haven't fixed#

Bing Webmaster Tools shows you whether Bing has indexed your site, which pages it's crawled, and how they rank for specific queries. Most brands have never claimed their account. Without it, you have no visibility into whether Bing can see your content at all.

Common gaps BrandCited finds in audits:

1. 1Sitemap not submitted to Bing. Google Search Console submissions don't carry over.
2. 2Site not verified in Bing Webmaster Tools.
3. 3IndexNow not implemented. This is the instant notification protocol that tells Bing when pages are published or updated.
4. 4Open Graph tags missing or incomplete. Bing weights these tags at a higher level than Google for initial page understanding.
5. 5Author metadata absent. Bing surfaces author credibility signals in a way that differs from Google's model.

The IndexNow protocol closes the fastest gap. As of January 2026, over 80 million websites use IndexNow, generating more than 5 billion daily URL submissions. Yet most individual brand sites still haven't implemented it. A new page published without IndexNow may not appear in Bing's index for weeks, which means it's also absent from ChatGPT's citation pool during that window.

How to fix your Bing indexing in under an hour#

This is the complete setup, in order of impact.

Go to bing.com/webmasters, sign in with a Microsoft account, and add your site. Verify ownership using an XML file upload, meta tag, or CNAME record. Verification takes under five minutes. Without this, you can't submit a sitemap or see crawl errors.

Once verified, go to Sitemaps in the left navigation. Submit your sitemap URL, which is yourdomain.com/sitemap.xml for most sites. Bing processes sitemaps at least once every 24 hours after initial submission. If you publish new content often, submit both an XML sitemap and a news sitemap.

IndexNow sends instant indexing requests to Bing, Yandex, and Naver when you publish or update content. Google doesn't support IndexNow, but that's not the goal here.

# IndexNow setup for custom stacks

# 1. Generate a key at bing.com/webmasters/indexnow
# 2. Upload the key file to your domain root:
#    https://yourdomain.com/{key}.txt
#    File contents: the key value only

# 3. Submit URLs via the IndexNow API on publish/update:
POST https://api.indexnow.org/indexnow
Content-Type: application/json

{
  "host": "yourdomain.com",
  "key": "your-key-value",
  "keyLocation": "https://yourdomain.com/your-key.txt",
  "urlList": [
    "https://yourdomain.com/new-page",
    "https://yourdomain.com/updated-page"
  ]
}

For WordPress, Yoast SEO and Rank Math both ship with IndexNow support built in. Enable it in one click. For Next.js and other custom stacks, call the API from your publish pipeline.

Bing uses Open Graph tags for initial page understanding, including how to categorize content and assess freshness. Every page needs these set:

<meta property="og:title" content="[Page title]" />
<meta property="og:description" content="[Page description]" />
<meta property="og:url" content="[Canonical URL]" />
<meta property="og:type" content="article" />
<meta property="article:published_time" content="[ISO 8601 date]" />
<meta property="article:modified_time" content="[ISO 8601 date]" />
<meta property="article:author" content="[Author name]" />

The article:modified_time tag matters for freshness signals. Bing weights updated content higher and this tag is the fastest signal. Update it every time you refresh a page.

The Seer Interactive study found that Bing-indexed third-party articles drove ChatGPT brand mentions with stronger correlation than direct domain citations. Getting your brand mentioned in articles that rank on Bing for relevant queries matters as much as ranking on Bing yourself. Target industry publications, guest posts, and analyst coverage that earns Bing positions for your key search terms.

AI search updates from the last 24 hours#

• GPT-5.5 brand citation shift: A Writesonic study of 1,257 citations found that GPT-5.5 cites brand websites 47% of the time, down from 57% on GPT-5.4, driven by a collapse in site: operator use from 40.5% to 12.6%. (Writesonic)
• Google AI Overviews in Drive: Google AI Overviews in Google Drive became available for Rapid Release domains on April 22, 2026, expanding AI-generated summaries from search into enterprise document tools. (Google Workspace Updates)
• Perplexity adds GPT-5.4: Perplexity added GPT-5.4 as a model option for Pro and Max subscribers alongside its Model Council feature, which lets users choose which AI handles each query. (Perplexity changelog)
• Gemini in cars: Google began rolling out Gemini to vehicles with Google built-in, replacing Google Assistant in millions of cars starting April 30. (TechCrunch)

How BrandCited audits your Bing indexing#

BrandCited's audit engine checks Bing indexing status as one of its technical AI visibility signals. If your site is not indexed on Bing, BrandCited flags it as a critical finding, because without Bing indexing, ChatGPT citation is not possible regardless of content quality or Google ranking.

BrandCited also checks for IndexNow implementation, Open Graph completeness, author metadata, and sitemap submission status. Each finding includes an exact fix, ranked by its impact on your AI visibility score across all 9 platforms BrandCited monitors. Run a free audit at brandcited.ai to see your current Bing and ChatGPT citation status.

What to do right now#

1. 1Verify your site in Bing Webmaster Tools at bing.com/webmasters. Free. Takes under five minutes. Without it you have no visibility into your Bing crawl status or indexing errors.
2. 2Submit your XML sitemap to Bing. Google Search Console submissions don't transfer. These are separate indexes with separate submission systems.
3. 3Implement IndexNow. Every new page or content update should trigger an IndexNow API call. On WordPress, enable it in Yoast or Rank Math. On custom stacks, call the API from your publish pipeline using the example above.
4. 4Audit your Open Graph tags. Check that every page has og:title, og:description, og:url, article:published_time, article:modified_time, and article:author set. Missing or stale dates hurt Bing freshness signals.
5. 5Build brand mentions in Bing-indexed third-party content. Guest posts, press coverage, and industry roundups that rank on Bing for your key terms drive ChatGPT brand mentions independent of your direct domain ranking.
6. 6Run a BrandCited audit. BrandCited shows your Bing indexing score alongside citation rates across ChatGPT, Perplexity, Gemini, and six other AI platforms. A free scan takes 30 seconds and flags every gap in order of impact.

ChatGPT has 900 million weekly users and its search recommendations drive real brand discovery. Those recommendations flow through Bing's index. Your Google ranking is irrelevant to them. Fix the Bing gap, then run a BrandCited audit to confirm your status across all 9 AI platforms in 30 seconds.

Frequently asked questions about ChatGPT citations and Bing#

No. ChatGPT's web search uses Bing's index, not Google's. A page that ranks on Google but isn't indexed on Bing won't appear in ChatGPT citations. You need separate optimization for Google AI Overviews, which uses Google's index, and for ChatGPT, which uses Bing's. BrandCited's audit checks both and shows you which gaps affect each platform.

The technical foundation overlaps. Both need crawlable pages, clean meta tags, and backlinks. The key differences for ChatGPT: Bing requires its own sitemap submission in Bing Webmaster Tools, weights Open Graph tags at a higher level in page understanding, and indexes content faster when IndexNow is implemented. Bing's index is separate from Google's, and Google Search Console data doesn't carry over. For ChatGPT visibility, Bing is the priority index to optimize.

Bing indexes new pages within 24 to 72 hours after sitemap submission in most cases. With IndexNow, Bing can index a new URL within hours of publication. Without sitemap submission or IndexNow, Bing may not discover new pages for weeks, or miss them.

Search for site:yourdomain.com in Bing. If you see your pages listed, Bing has indexed them. For crawl errors, indexing coverage, and query performance data, use Bing Webmaster Tools. BrandCited's audit also checks Bing indexing status as part of its technical checks and flags any gaps with specific fixes.

Get your site indexed and ranking on Bing for queries your customers ask. ChatGPT's web search retrieves from Bing's top results 87% of the time. Claim Bing Webmaster Tools, submit your sitemap, implement IndexNow, and build brand mentions in third-party content that ranks on Bing. BrandCited tracks ChatGPT citation rates across your target queries so you can measure progress over time.

For real-time web search, yes. ChatGPT agents rely on Bing's Search API 92% of the time when retrieving web content. The model's training data is a separate layer. For citation tracking purposes, web search mode is what determines which brand pages ChatGPT links to in responses.