In short. AdIdxBot follows Bing Ads to destination websites for quality control and identifies itself with the adidxbot user-agent token.
Definition: AdIdxBot is the Bing Ads crawler, an automated program that visits advertisements and their destination websites for quality control. As of 17 October 2026, Bing documents desktop and mobile variants.
Key facts
- Bing's crawler documentation assigns AdIdxBot the task of following ads to their destination websites for quality control.
- Bing's robots.txt tester documentation provides a choice between Bingbot and AdIdxbot when testing a URL.
- The Verifying Bingbot guide describes reverse and forward DNS lookups to check the origin of Bingbot requests.
What does an AdIdxBot request identify?
A landing page is the destination page linked from an advertisement. Bing's crawler overview places visits to those websites within AdIdxBot's advertising quality-control role. It separately describes Bingbot as its standard crawler handling most daily crawling.
A user agent is an identifier sent with a request. The same overview supplies this desktop AdIdxBot user-agent string:
Mozilla/5.0 (compatible; adidxbot/2.0; +http://www.bing.com/bingbot.htm)
The documented mobile examples also contain adidxbot/2.0. The shared bingbot.htm address in the string links to Bing's crawler information; the identifying token here is adidxbot. A log review can use that token to separate requests presenting themselves as AdIdxBot from requests presenting themselves as Bingbot.
How is the request's origin checked?
Bing's crawler overview warns that user-agent strings can be faked and directs readers to Verify Bingbot and its verification methods. The string therefore identifies a claimed crawler identity, while the request's source IP address provides the input for verification.
The linked Verifying Bingbot guide describes a reverse DNS lookup, which maps an IP address to a hostname ending in search.msn.com. A forward lookup then resolves that hostname back to the original IP address. These detailed instructions are written for Bingbot; the guide leaves AdIdxBot-specific verification undocumented.
How can landing-page access be tested?
A robots.txt file contains instructions about crawler access. Bing's tester guide describes entering the landing-page URL in Test URL, selecting AdIdxbot, and choosing Test to check blocking rules for that user agent.
The test uses the contents of the editor. After an edit, another test checks the changed rules. This distinction matters when reviewing a proposed change before it reaches the website. The guide also describes downloading the edited file and uploading it to the domain's root directory, where robots.txt belongs.
After the website's file changes, Fetch latest retrieves the property's latest robots file. The tester can then check the landing-page URL against that retrieved version.
Related terms
FAQ
Where can I find the AdIdxBot identifier?
You can look for adidxbot/2.0 in the request's user-agent value. Bing documents it in both desktop and mobile examples.
Can I test an advertising URL separately from Bingbot?
You can select AdIdxbot in Bing's robots.txt tester and enter the destination URL in Test URL. The test checks that URL against the editor's rules for the selected user agent.
Sources
- Bing Webmaster Tools, "Overview of Bing crawlers (user agents)", undated
- Bing Webmaster Tools, "Robots.txt tester", undated
- Bing Webmaster Tools, "Verifying Bingbot", undated
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