Detect Bingbot from User-Agent String
Identify Microsoft's Bingbot crawler from User-Agent strings. Covers Bingbot variants, verification methods, and crawl behavior differences from Googlebot.
Detailed Explanation
Identifying Bingbot in User-Agent Strings
Bingbot is Microsoft Bing's web crawler. While it handles a smaller share of search traffic than Google, it powers not only Bing but also Yahoo Search results in many markets, making it a significant crawler to monitor.
Bingbot UA Strings
Standard Bingbot:
Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)
Bingbot rendering as Evergreen Chrome:
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm) Chrome/116.0.1938.76 Safari/537.36
Since 2019, Bingbot adopted the Chromium rendering engine. This means it renders JavaScript-heavy pages similarly to Chrome, but its UA still includes the bingbot/2.0 identification token.
Other Microsoft Crawlers
- BingPreview — Generates page thumbnails for Bing search results
- MicrosoftPreview — Similar to BingPreview for Microsoft products
- msnbot — Legacy MSN Search crawler (largely replaced by bingbot)
- AdIdxBot — Bing Ads quality checker
Bingbot vs. Googlebot Differences
| Aspect | Googlebot | Bingbot |
|---|---|---|
| Engine | Chromium (evergreen) | Chromium (evergreen) |
| Crawl rate | Adaptive, aggressive | More conservative |
| robots.txt | Respects Googlebot rules | Respects bingbot rules |
| JavaScript | Full rendering | Full rendering |
| Identification | Googlebot/2.1 |
bingbot/2.0 |
Verification
To verify an authentic Bingbot request:
- Reverse DNS the IP — should resolve to
*.search.msn.com - Forward DNS the hostname — should resolve back to the original IP
- Microsoft publishes Bingbot IP ranges via their documentation
Use Case
SEO professionals monitor Bingbot crawl behavior to optimize for Bing search results, which power Yahoo search in many regions. DevOps teams use Bingbot detection to configure crawl rate limiting separately from Googlebot and other crawlers.