Bing announced a new set of mobile crawlers with Bingbot Mobile User Agents to better support and recognize mobile websites that are not responsively designed.

Lee Xiong from the Bing Crawl team explained Bing has designed these new crawlers to “probe websites with a number of new crawlers with the aim to give us the best representation of what our users can expect from your website when viewed on their favorite device.” The new mobile spiders are named:

Mozilla/5.0 + (Mobile Device) + Mobile Engine + Mobile Browser + bingbot/BingPreview/[version]

Mozilla/5.0 (iPhone; CPU iPhone OS 7_0 like Mac OS X) AppleWebKit/537.51.1 (KHTML, like Gecko) Version/7.0 Mobile/11A465 Safari/9537.53 BingPreview/1.0b

Mozilla/5.0 (Windows Phone 8.1; ARM; Trident/7.0; Touch; rv:11.0; IEMobile/11.0; NOKIA; Lumia 530) like Gecko BingPreview/1.0b

Mozilla/5.0 (iPhone; CPU iPhone OS 7_0 like Mac OS X) AppleWebKit/537.51.1 (KHTML, like Gecko) Version/7.0 Mobile/11A465 Safari/9537.53 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)

Mozilla/5.0 (Windows Phone 8.1; ARM; Trident/7.0; Touch; rv:11.0; IEMobile/11.0; NOKIA; Lumia 530) like Gecko (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)

This gives Bing a better method of seeing how iPhone users see your site versus desktop users or Android tablets. With this, Bing, like Google, recommends you do not block JavaScript or CSS from Bing’s crawlers. It wants to be able to render the pages like users.

Bing still recommends that you deploy a single URL/website approach and go with a responsive design. But it also does understand it is not the practice every site is taking, and thus, it is adapting to understand mobile sites that are not responsively designed. So with this, Bing is checking if your site is mobile “compatible,” and if so, responsive versus another format.