MicrosoftPreview
Microsoft Bing operates MicrosoftPreview, which generates page snapshots for Microsoft products in desktop and mobile variants. Bing does not document a robots.txt token for it or state whether it honors robots.txt. Bing documents no verification method for MicrosoftPreview specifically; its generic guidance for all Bing crawlers covers the Verify Bingbot tool, reverse DNS to search.msn.com and the bingbot.json range file.
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; MicrosoftPreview/2.0; +https://aka.ms/MicrosoftPreview) Chrome/W.X.Y.Z Safari/537.36What MicrosoftPreview does
The desktop variant appears in logs as a Chrome-like User-Agent with MicrosoftPreview/2.0 and a link to aka.ms/MicrosoftPreview; the mobile variant uses an Android Nexus 5X Chrome User-Agent carrying the same token. The aka.ms link redirects to the Bing help article that lists its crawlers. Bing says the bot generates page snapshots for Microsoft products, but does not say which products display them or how often a page is fetched.
Bing does not document a robots.txt token for MicrosoftPreview and does not state whether it reads robots.txt at all, so the effect of a Disallow rule is undocumented. Bing publishes no IP range list specific to this bot and no reverse DNS suffix for it. The only verification guidance is the generic statement for all Bing crawlers, which names the Verify Bingbot tool, reverse DNS to search.msn.com and the bingbot.json file. Blocking the bot stops the page snapshots Bing describes; the documentation does not say what losing those snapshots changes in any Microsoft product. The registry files it as social-preview as the closest category, a term Bing does not use.
Operator note. The mobile user agent is Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/W.X.Y.Z Mobile Safari/537.36 (compatible; MicrosoftPreview/2.0; +https://aka.ms/MicrosoftPreview). The https://aka.ms/MicrosoftPreview link in the user agent redirects to the Bing crawlers help article. The documentation does not state which Microsoft products use it.
Controlling MicrosoftPreview with robots.txt
Use the token undocumented in robots.txt. Microsoft Bing's documentation does not state whether this bot honors robots.txt.
User-agent: undocumented
Disallow: /User-agent: undocumented
Allow: /Verifying a request is really MicrosoftPreview
Anyone can put MicrosoftPreview/2.0 in a User-Agent header. Microsoft does not document a verification method specific to MicrosoftPreview. The generic guidance for all Bing crawlers applies: use the Verify Bingbot tool, check that reverse DNS resolves to a hostname under search.msn.com, or match the IP against the published list at https://www.bing.com/toolbox/bingbot.json.
Common questions
Does MicrosoftPreview obey robots.txt?
The operator's documentation does not say. The Bing crawlers help article lists MicrosoftPreview with its User-Agent strings and its purpose, but names no robots.txt token for it and makes no statement about whether it reads robots.txt or how it treats a Disallow rule.
How do I verify MicrosoftPreview?
Bing gives no method specific to MicrosoftPreview. Its help article has only the generic guidance for all Bing crawlers: the Verify Bingbot tool in Bing Webmaster Tools, a reverse DNS lookup resolving to search.msn.com, or the bingbot.json IP range file. Bing does not state whether those apply to MicrosoftPreview.
What is MicrosoftPreview used for?
Bing says it generates page snapshots for Microsoft products and has desktop and mobile variants, each with its own User-Agent string. The help article does not say which products show the snapshots, how often the bot fetches a page, or whether it executes JavaScript.
Sources
Every fact on this page was checked against Microsoft Bing's own documentation, listed below, and re-checked by a second reviewer before publication. Reviewed September 2026.
Related crawlers
This registry documents how operators describe their own bots so site owners can identify and control them. It does not publish third-party IP lists or guess at undocumented behaviour. To see how your own site responds to automated visitors, the bot detection scanner reads a URL's live response and names the protection it finds.