What Is Bingbot? Definition and How It Works

Bingbot is Microsoft's automated web crawling system that discovers, fetches, and indexes web pages for Bing Search. It works similarly to Googlebot but builds a separate search index used by Bing. In the AI era, Bingbot's importance has grown dramatically because Bing's index also powers Microsoft Copilot and serves as the search backend for ChatGPT's web browsing feature. Blocking Bingbot means blocking your content from two of the three largest AI platforms.

Why It Matters

For over a decade, Bingbot was the less important sibling of Googlebot. Bing held roughly 3-5% of global search market share, and many webmasters paid it little attention. The AI revolution has fundamentally changed this dynamic.

Microsoft Copilot -- integrated into Windows, Edge, Office 365, and Bing Search -- uses Bing's index as its knowledge base. When Copilot answers a question using web data, it retrieves that data from pages Bingbot has indexed. Copilot's user base is growing 25x year-over-year, making it one of the fastest-growing AI platforms.

Even more significantly, ChatGPT uses Bing as its search provider when browsing the web. When a ChatGPT user asks a question that requires current information, ChatGPT queries Bing's index to retrieve relevant pages. ChatGPT accounts for 84.2% of all AI referral traffic and converts at 4.4x the rate of organic search. The content it retrieves comes, in large part, from Bing's index.

This means Bingbot now serves as the crawler behind three major platforms: Bing Search, Microsoft Copilot, and ChatGPT browsing. Blocking Bingbot -- even accidentally -- eliminates your visibility across all three. For proper configuration, see our guide on robots.txt for AI crawlers.

How It Works

Bingbot operates through a crawl-index cycle similar to Googlebot but with its own infrastructure and behaviors.

Discovery. Bingbot finds pages through links on already-indexed pages, XML sitemaps submitted via Bing Webmaster Tools, IndexNow notifications for real-time discovery, and URL submissions through Bing Webmaster Tools' API.

Crawling. Bingbot sends HTTP requests to your server using the user-agent string bingbot. It respects robots.txt directives, crawl-delay headers, and HTTP caching headers. Bingbot crawls from IP addresses in documented ranges that can be verified via reverse DNS lookup.

Rendering. Bingbot can execute JavaScript, though it tends to be more conservative than Googlebot in how it handles JS-rendered content. Server-side rendered pages are more reliably crawled and indexed by Bingbot.

Indexing. After processing a page, Bing decides whether to include it in the search index. Indexed pages become available to Bing Search, Copilot, and ChatGPT's browsing feature. Bing's indexing criteria differ from Google's -- pages that rank well in Google may not be indexed the same way in Bing.

Crawl rate. Bingbot adjusts its crawl rate based on your server's response time and capacity. You can set a crawl-delay directive in robots.txt specifically for Bingbot, though setting it too high can slow down indexing of new content.

Key user-agents to know:

• bingbot -- The main search crawler for Bing's index
• MicrosoftPreview -- Used for generating URL previews
• adidxbot -- Bing's advertising crawler

For AI SEO purposes, ensuring bingbot has full access is the priority.

Practical Implications

• Check your robots.txt for Bingbot rules. Some websites block Bingbot without realizing the downstream impact on Copilot and ChatGPT. Verify that bingbot is not listed in any Disallow rules for pages you want AI to find.
• Submit your sitemap to Bing. Many sites only submit sitemaps to Google. Bing Webmaster Tools accepts sitemap submissions and supports IndexNow for real-time indexing notifications.
• Verify Bing indexing separately. Do not assume that pages indexed in Google are also indexed in Bing. Search site:yourdomain.com on Bing or use Bing Webmaster Tools' URL Inspection to check.
• Prioritize server-side rendering. Bingbot is less aggressive at JavaScript rendering than Googlebot. If your content requires JS to display, Bingbot may miss it. Use SSR or pre-rendering for critical pages.
• Monitor your Copilot visibility. After confirming Bingbot can access your pages, check whether Copilot is actually citing your content. Being indexed is necessary but not sufficient for AI citation.