How to verify Bingbot
The Bingbot user agent is commonly spoofed, so a request claiming to be Bingbot should be verified rather than trusted. Microsoft documents a reverse-DNS method: the source IP should resolve into search.msn.com, confirmed by a forward lookup back to the same IP. Bing also publishes IP information for verification.
The reverse-DNS method
Microsoft documents reverse DNS as the way to verify Bingbot. Look up the source IP and confirm the hostname resolves into search.msn.com, then run a forward DNS lookup on that hostname and confirm it returns the original IP. Both directions must agree for the request to be genuine Bingbot.
This differs from Google's googlebot.com domain only in the hostname you expect: for Bing, it is search.msn.com. The two-direction principle is the same.
- Reverse DNS must resolve into search.msn.com
- Forward lookup must return the original IP (both directions)
- Bing also publishes IP information to support verification
Why this matters
As with Googlebot, scrapers copy the Bingbot user-agent string to bypass rules that allow search crawlers. Decisions made on the string alone — serving full content, relaxing limits — can be exploited by a fake Bingbot.
Verifying via reverse DNS turns the claim into a fact. Use Bing Webmaster Tools documentation for the current, authoritative verification procedure, since the supported methods can be updated.
How it appears in analytics and logs
A user agent that says bingbot is only a claim. Verification tells you whether the request truly came from Microsoft's crawler infrastructure. An unverified Bingbot string that does not resolve into search.msn.com is likely fake Bingbot from a scraper.
Diagnostic use case
Confirm a request that claims to be Bingbot is genuinely Microsoft before trusting it for log analysis, access decisions, or serving behaviour.
What WebmasterID can help detect
WebmasterID classifies crawlers server-side and separates verified Bingbot from spoofed lookalikes, so you can see genuine Bing crawl coverage without manually running DNS checks on each request.
Common mistakes
- Trusting the bingbot user-agent string without reverse-DNS verification.
- Expecting Bingbot to resolve into googlebot.com — it resolves into search.msn.com.
- Skipping the forward-confirm step after the reverse lookup.
Privacy and accuracy notes
Verification operates on the request's IP and DNS records, not on any human identity — a crawler is not a person. WebmasterID treats verified crawlers as bot events kept out of human analytics.
Related pages
- Bingbot — Microsoft Bing's web crawler
Bingbot is the crawler Microsoft Bing uses to discover and index web pages. It uses the bingbot robots.txt token and can be verified through Bing's reverse-DNS method and published IP ranges. Bing also powers results for other surfaces, so Bingbot coverage has reach beyond Bing.com.
- How to verify Googlebot
The Googlebot user agent is widely spoofed, so a request claiming to be Googlebot should be verified, not trusted. Google documents two methods: a reverse-DNS check that resolves into googlebot.com or google.com confirmed by a matching forward lookup, and matching the source IP against Google's published crawler IP ranges.
- Fake search-bot traffic
Because search-engine crawlers are widely allowed, abusive clients copy the Googlebot or Bingbot user-agent string to slip past rules meant for real crawlers. This fake search-bot traffic is identified by verifying the source: genuine crawlers pass reverse-DNS and published-IP checks, spoofed ones do not.
- Bot intelligence
Verified crawler classification separated from human traffic.
Sources and verification notes
- Bing — Verifying BingbotDocuments reverse-DNS verification into search.msn.com.
Last reviewed 2026-06-24. Facts are checked against primary/official sources where available; uncertain specifics are marked “Data not yet verified” rather than guessed.