Copilot is based on Bing's index: what this means for source selection
Microsoft Copilot retrieves its web results from Bing's index. If a page isn't indexed in Bing, Copilot can't use it as a source, no matter how well the page ranks in Google.
Microsoft itself describes the mechanics. Step two in Copilot Chat’s architecture is called “web grounding” via the Bing search service. Copilot rewrites the user’s prompt into a short search query consisting of just a few words and sends it to Bing. The query is not the user’s full prompt, and it contains neither the user ID nor the tenant ID. The content returned by Bing is what the language model uses to generate its response. The source is Microsoft’s documentation on Copilot Chat, last updated on August 18, 2026.
Bing refers to these queries as grounding queries. At the same time, Microsoft has been explicit that the index now serves two distinct purposes. In May 2026, the Bing team put it this way: “Search indexing was built to help humans decide what to read. Grounding indexing is being built to help AI systems decide what to say.” The same index, two purposes. Classic search is meant to help a person choose a link. Grounding is meant to provide a model with material it can vouch for.
This specifically changes the choice of sources. Bing explains that the focus is shifting from documents to what they call “groundable information”: well-defined facts with a clear provenance. A page that makes a claim without specifying who, when, and how many is difficult to ground. A page with named sources, dates, and numbers is easy to ground. This is the same discipline we apply when we build Visibility in AI Search for customers.
We organize the work around four gates. InboundCPH's Four Ports for Copilot is the sequence a page must go through before it can be used as a source in a Copilot response. If a port is skipped, the chain stops there.
The page is included in Bing's index
Bing must be able to crawl and index the URL. If it is blocked in robots.txt, set to "noindex," or has never been discovered, it will not appear in Copilot. Check the status in Bing Webmaster Tools under URL Inspection.
The domain has been verified with Microsoft
Without a verified domain in Bing Webmaster Tools, you won't have any data on what Copilot is fetching. Verification is free and typically takes less than ten minutes when importing from Google Search Console.
The content can be used as evidence
The text must contain specific facts with a source, date, and unit so that a model can use them without having to guess. Vague statements without a source are difficult to ground.
The citations are followed
The AI Performance report in Bing Webmaster Tools shows which pages are cited and which grounding queries trigger the citation. Without measurement, optimization is just guesswork.
Copilot in Microsoft 365: How B2B Buyers Search During Work Hours
Danish B2B buyers most often encounter Microsoft Copilot within their work tools, not on bing.com. Copilot is integrated into Teams, Outlook, Word, and Edge, and that is where a large portion of professional research takes place during work hours.
The figure has been confirmed by Microsoft itself. Microsoft 365 Copilot has surpassed 30 million paid seats. This figure comes from the financial results for the fourth quarter of fiscal year 2026, which ended June 30, 2026, and was published on July 29, 2026. Microsoft has also renamed the product: Microsoft 365 Copilot is now called Microsoft Copilot, and Microsoft 365 Copilot Chat is now called Microsoft Copilot Chat.
This changes how market share figures should be interpreted. In August 2026, StatCounter reported that Bing accounted for 9.29 % of searches in Denmark, compared to Google’s 84.65 %. This type of measurement covers browser-based search traffic. A grounding query that Copilot sends to Bing from within Outlook does not appear as a Bing search in browser data. Bing’s actual impact on Danish B2B purchasing processes is therefore greater than 9.29 %, but exactly how much greater cannot be precisely documented at this time. Treat this figure as a minimum estimate, not as a definitive figure.
These three platforms have different requirements for your content.
| Flat | Where the buyer is | What Determines Whether You Become a Source |
|---|---|---|
| Copilot Chat in Teams, Outlook, and Word | In the middle of the workday, often during the research phase before compiling a list of suppliers | The page must be in Bing's index and match the short grounding query that Copilot formulates itself |
| Copilot in Edge on a blank page | On your own website or a competitor's website | No grounding query is sent. The model reads the page directly, so the page's own text and structure determine the answer |
| AI responses on bing.com | In a standard search | Classic Bing visibility plus the ability to provide a concise, well-documented answer |
There are two caveats to keep in mind before anyone builds a business plan based on this data. An IT department can disable web grounding for the entire organization in the Microsoft 365 Admin Center, in which case no external sources are included in the responses. And Copilot Chat displays the actual search queries in the citations section below the response, but only for 24 hours. The scope is real, but it is neither guaranteed nor fully measurable.
Bing Webmaster Tools: How to Track Citations in Copilot
The AI Performance report in Bing Webmaster Tools shows how often your pages are cited in AI-generated responses. Microsoft launched the report in public preview on February 10, 2026, and it covers Microsoft Copilot, AI-generated summaries in Bing, and select partner integrations.
The report includes five key metrics: total number of citations, average number of cited pages per day, the grounding queries the AI used to retrieve the content, citations per URL, and trends over time. Microsoft itself is clear about the limitations. Data on grounding queries represents a sample of overall citation activity, not a complete count. The figures per page reflect frequency, not ranking, authority, or the page’s role in the individual response. Therefore, treat the report as a guide rather than a definitive list of answers.
On June 16, 2026, Microsoft expanded the report globally in preview with four features that shift the focus from individual keywords to context and market share.
The intention behind the quotation
Intents categorizes the grounding queries that trigger citations into types such as Informational, Commercial, Navigational, Research, and Local. This indicates whether the content reaches the user during the research phase or closer to a decision.
Thematic visibility over keywords
Topics group related grounding queries into thematic clusters. Topics show the subject areas in which a site is building authority in Bing and where content is lacking.
Your share of the citations
Citation Share is the percentage of all citations for the same grounding query that your site accounts for. It is a percentage, not an absolute number, and is therefore useful as a measure of Share of Voice relative to competitors.
Trends Over Time
Compare superimposes a previous time period over the current one in Bing Webmaster Tools, making fluctuations in citation activity visible. Compare is the feature that links a content initiative to a subsequent change in citations.
Microsoft itself refers to these features as “early preview innovations,” where quality and coverage are expected to improve as the models mature. The honest takeaway for management is therefore: use the numbers to prioritize content, not to report on market share.
Get Started with Bing Webmaster Tools in Five Steps
Create an account
Go to bing.com/webmasters and sign in with a Microsoft, Google, or Facebook account. If you already have a Microsoft account for Outlook, Teams, or Microsoft 365, you can use it right away.
Add your website
The fastest way is to import from Google Search Console. Bing automatically fetches sites, verifies ownership, and retrieves existing sitemaps, so your site will be ready in just a few minutes. Alternatively, you can add the site manually using the full URL.
Verify ownership
When adding a site manually, ownership must be verified using an XML file in the root directory, a meta tag on the homepage, or a CNAME DNS record. The DNS method is often preferable because it remains valid even when the site's files are changed.
Submit your sitemap
And correct sitemap helps Bing find and index pages faster. Most sites already have it at ditdomæne.dk/sitemap.xml. Submit it under "Sitemaps" and enable "IndexNow" at the same time.
Review the reports
Once Bing starts collecting data, you'll have access to Search Performance, Site Explorer, URL Inspection, backlinks, and the AI Performance report. Expect it to take a few days before meaningful data becomes available.
Glossary: Terms Used in the Report
| Concept | What this means in practice |
|---|---|
| Grounding query | The short search query that Copilot generates based on the user's prompt and sends to Bing. It is rarely identical to what the user typed. |
| Grounding | When an AI model uses your content as documented evidence in its response. The goal of the Copilot project is to become a reliable source of grounding. |
| Citation | A reference to your content in an AI-generated response in Copilot or Bing. Similar to a blue link, but within the response itself. |
| Citation Share | Your percentage share of all citations for the same grounding query. Essentially, a "Share of Voice" metric for AI responses. |
IndexNow: From Publication to Copilot Responses
IndexNow is a protocol that immediately notifies participating search engines when a URL is new or has been updated. It reduces the time from publication to the point when Bing can include the page in its index, thereby making it available for Copilot’s grounding.
According to IndexNow.org, Bing, Yandex, Seznam.cz, Naver, Yep, and Amazon participate in the protocol. A submission to a single endpoint is shared with all participating search engines. Google is not on the list of participants, and IndexNow is therefore a Bing and Copilot tool, not a Google tool. Technically, up to 10,000 URLs can be sent per POST request, and the key must be 8 to 128 characters long, consisting of uppercase and lowercase letters, numbers, and hyphens.
Generate and place the key
Create an IndexNow key consisting of 8 to 128 characters, including letters, numbers, and hyphens. Place it as a text file in the site’s root folder, for example, ditdomæne.dk/nøgle.txt, with the key as its sole content. This file serves as Bing’s proof that you own the domain.
Connect a CMS or CDN
WordPress can automatically send IndexNow pings via a plugin, and Cloudflare offers built-in integration at the CDN level. Choose one source to send from to avoid duplicate submissions.
Submit only when there are actual changes
Submit when adding new pages or updating content, not every time you clear the cache. IndexNow does not publicly disclose its rate limits, and an HTTP 429 error indicates that the limit has been reached.
Managing expectations is important. IndexNow itself states that a submission does not guarantee immediate indexing, but it does increase the likelihood that important changes will be detected and crawled more quickly. Notification is not the same as indexing, and indexing is not the same as citation. The benefit is time, and time matters most for content that is current.
How to Optimize for Bing Without Harming Google
There is no documented Bing optimization that harms Google. Only two strategies are truly Bing-specific: verification in Bing Webmaster Tools and IndexNow. The rest of the work is the same as what also improves organic visibility on Google.
Google itself is clear on this point. Search Central’s documentation on AI features states that there are no additional requirements for appearing in AI Overviews or AI Mode. You do not need new machine-readable files, AI text files, or special schema.org markup. Bing, on the other hand, requires well-defined facts with clear provenance. These two requirements point in the same direction: named sources, dates, and numbers in the visible text.
| Effort | Performance in Bing and Copilot | Impact on Google |
|---|---|---|
| Verification in Bing Webmaster Tools | Access to AI Performance Data and URL Inspection | None. Pure data gain with no risk |
| IndexNow | Faster detection of new and updated content | None. Google does not participate in the protocol. |
| Facts with the source, date, and unit included in the text | Make the content available to Copilot | Supports E-E-A-T and citability in AI Overviews |
| Technical accessibility: robots.txt, sitemap, canonicals | Determine whether the page will be included in Bing's index at all | Same requirement for Google's index |
| Internal link structure between pillars and clusters | Topics help bring you together around a subject | Classic Subject Authority |
The order is often reversed. Verify in Bing Webmaster Tools first, and then enable IndexNow. Without verification, you won't have any data to assess whether IndexNow made a difference.
Data is just the first step
Bing Webmaster Tools provides the insights, but it’s the interpretation and execution that drive results. Turning citation data into business value requires an understanding of both the fundamentals, technical SEO, and the actual buyer’s journey. That’s where the interplay between data, software, and Experienced AI SEO experts makes all the difference. That’s also the approach we take when we work with AI-SEO across channels.
Frequently Asked Questions About Microsoft Copilot and Bing
Does Microsoft Copilot use Bing's index?
Yes. In its documentation on Copilot Chat, Microsoft explains that grounding is done through the Bing search service. Copilot sends a short, automatically generated search query to Bing and bases its response on the results it receives. If a page isn’t in Bing’s index, it cannot be included in the response.
What is a grounding query?
A grounding query is the short search query consisting of just a few words that Microsoft Copilot formulates itself based on the user’s prompt and sends to Bing. It is not identical to the user’s prompt, and it contains neither the user ID nor the tenant ID. Bing Webmaster Tools displays a sample of the grounding queries that have triggered citations of your pages.
How big is Bing in Denmark?
StatCounter reported that Bing accounted for 9.29 % of searches in Denmark in August 2026, compared to Google’s 84.65 %. That figure covers browser-based search traffic. Grounding queries from Microsoft Copilot within Microsoft 365 are not included, so Bing’s importance for B2B research is greater than its market share alone suggests.
Does IndexNow work with Google?
No. IndexNow.org lists Bing, Yandex, Seznam.cz, Naver, Yep, and Amazon as participating search engines. Google is not among them. IndexNow is therefore a tool for faster discovery in Bing—and thus in Microsoft Copilot—while Google continues to discover content through crawling and sitemaps.
Why is Citation Share important?
Citation Share shows your percentage share of all citations for the same grounding query. This allows you to assess your relative strength compared to competitors, rather than just looking at absolute numbers. Microsoft itself describes the feature as an early preview innovation, so use the number to prioritize content and not as an exact market share.
Is it possible to optimize for Bing without hurting Google?
Yes. Only two actions are specific to Bing: verification in Bing Webmaster Tools and IndexNow, and neither of them affects Google. Google’s Search Central also states that no special files or schema.org markup are required to appear in AI Overviews and AI Mode. Facts that include a source and date in the visible text help both platforms.
Does Bing Webmaster Tools cost anything?
No. Bing Webmaster Tools is free, including the AI Performance report and the Intents, Topics, Citation Share, and Compare features. The fastest way to set it up is to import from Google Search Console, where Bing automatically retrieves sites, ownership verification, and existing sitemaps.
Get an overview of your visibility in Copilot and Bing
An AI visibility analysis shows how often your content is cited in Microsoft Copilot, Bing, and Google, and which topics you haven’t covered yet. We map out your visibility across these three platforms, identify the gaps, and create a prioritized plan.
Sources
- Microsoft Learn: Microsoft Copilot Chat Privacy and Protections, updated August 18, 2026
- Bing Search Blog: The Evolving Role of the Index, May 6, 2026
- Bing Webmaster Blog: Introducing AI Performance in Bing Webmaster Tools, February 10, 2026
- Bing Search Blog: New AI Visibility Insights in Bing Webmaster Tools, June 16, 2026
- Microsoft: FY26 Q4 Press Release, July 29, 2026
- StatCounter: Search Engine Market Share in Denmark, August 2026
- IndexNow.org: FAQ
- Google Search Central: AI Features and Your Website
Last updated September 6, 2026. This page is revised every 60 days because both the Copilot interface and Bing's AI reporting are changing rapidly.
