AI crawlers · Microsoft

bingbot

bingbot is a crawler operated by Microsoft, and it builds the index an assistant answers from — the fact that decides everything else on this page.

What does bingbot actually do?

Bingbot's index matters more than Bing's own share of searches suggests, because that index is what Microsoft Copilot retrieves from and what a number of other search products have been built on top of over the years. Blocking bingbot is not a single-engine decision - it removes you from everything downstream of the crawl.

It is also one of the few agents you can push to rather than wait for. Bing supports IndexNow, so you can notify it when a URL changes instead of hoping a recrawl arrives soon, and Bing Webmaster Tools exposes crawl-rate controls if volume rather than principle is the problem. Almost nothing else in this registry offers either.

Microsoft also runs a lookup page where you paste a single address and get an answer, which is the quickest way to settle an argument about one request without wiring up the range file. For anything ongoing, the forward-confirmed reverse DNS check is the cheaper automated option, since there is no file to keep refreshing.

One thing this registry cannot give you is a way to separate Bing's ordinary search from Microsoft's AI answers, because Microsoft publishes no distinct token for the second. The same crawl feeds both. That makes the decision coarser than it is at OpenAI or Anthropic, where the training, index and live-fetch jobs each carry their own name and can be allowed or denied independently of one another.

CrawlClick files bingbot as a search index crawl. What the three crawl purposes mean.

Microsoft runs one agent in this registry, which makes bingbot the whole of the decision. Vendors that split the work across several tokens let a publisher decline one job and keep another; Microsoft publishes no second name here, so there is nothing to separate. Whatever you settle on for bingbot governs every use Microsoft makes of your pages until another token appears — which is a coarser instrument than it looks, and worth weighing before the search index label decides it for you.

Should I block bingbot?

Bingbot is treated as optional because Bing's own share is small, and the cost only becomes visible later when Copilot and other Bing-derived products stop including the site.

To block it anyway, add this to robots.txt (how the rules resolve):

User-agent: bingbot
Disallow: /

Replace Disallow: / with Allow: / to permit it explicitly. A crawler that ignores robots.txt is not blocked by it either way — that is what verification and edge rules are for.

How do I verify bingbot is genuine?

Microsoft lets you check a request claiming to be bingbot against reverse DNS ending in .search.msn.com, published IP ranges. A user-agent header on its own proves nothing.

Its address list lives at https://www.bing.com/toolbox/bingbot.json, and its reverse-DNS names end in .search.msn.com.

The verification procedure explains why a reverse lookup has to be forward-confirmed, and why a published range list has to be re-fetched rather than pinned.

How do I find bingbot in my logs?

Match the user-agent against "bingbot", case-insensitively. Set the bingbot fetch count beside the visits Microsoft actually returns; that ratio is your crawl-to-referral gap for this engine.

Crawl-to-referral gap defines the ratio, and the rate-limiting guide covers what to do when the volume itself is the problem.

Registry last reviewed 2026-09-13.