# bingbot

> Bing's only crawler, and therefore also the crawler behind Microsoft Copilot's grounding. Microsoft's documented way to keep search indexing while refusing generative reuse is the nocache / noarchive robots meta directive, not a separate user-agent.

| field | value |
|---|---|
| operator | Microsoft |
| category | Search engines |
| robots.txt token | `bingbot` |
| user-agent contains | `bingbot` |
| robots.txt | obeys robots.txt (documented) |
| verify by | published IP ranges |
| published IP ranges | https://www.bing.com/toolbox/bingbot.json |
| prefixes mirrored | 28 IPv4 / 0 IPv6 |
| operator docs | https://www.bing.com/webmasters/help/which-crawlers-does-bing-use-8c184ec0 |
| last reviewed | 2026-09-14 |

## What blocking it costs you

Very high and very wide: Bing, Copilot, DuckDuckGo and several assistants that resell Bing's index all lose you at once. Use nocache/noarchive rather than blocking.

## Full user-agent string

```
Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)
```

## Block it

```
User-agent: bingbot
Disallow: /
```

## Allow it

```
User-agent: bingbot
Allow: /
```

## Ask this page a question, with one GET

A question about this page, answered by a call you can make right now — no key, no account, no JSON-RPC, nothing to assemble. The query string is already filled in with this page's own subject.

- **How do I prove a request really is bingbot?**  
  `curl -s 'https://www.pathwren.workers.dev/tools/verification-methods?crawler=bingbot&s=client-dossiers'`  
  The verification method its operator actually publishes — published IP ranges, reverse DNS, or nothing at all — and the mirror of it on this host.
- **Is 13.66.139.0 really bingbot?**  
  `curl -s 'https://www.pathwren.workers.dev/tools/verify-crawler?ip=13.66.139.0&ua=bingbot&s=client-dossiers'`  
  That address checked against every prefix this host mirrors. 13.66.139.0 is the first address of 13.66.139.0/24, one of the ranges listed on this page — so the link is a worked example that returns a match. Swap in an address from your own log.

Every parameter above is a value the endpoint reads, not an address it visits: nothing is fetched on your behalf. Called without any parameter, each endpoint returns its own specification instead of an error.

JSON: https://www.pathwren.workers.dev/crawler/bingbot.json · index: https://www.pathwren.workers.dev/llms.txt