Safe Official docs Search Engines

Microsoft Preview

Operated by Microsoft

Quick Facts

User-Agent:
MicrosoftPreview
Category:
Search Engines
Operator:
Microsoft
Safety:
Safe
Blocking Impact:
Low - No SEO ranking impact
SEO Impact Score:
2/10
Official docs:
www.bing.com

Confirmed by the operator

Microsoft names MicrosoftPreview on its own documentation page, linked above. The token, purpose and robots.txt behaviour on this profile come from that page, re-checked on September 22, 2026.

What is Microsoft Preview?

Microsoft Preview is an AI crawler operated by Microsoft. It uses the user-agent string MicrosoftPreview and follows the Robots Exclusion Protocol.

Microsoft Preview is an AI crawler operated by Microsoft. It uses the user-agent string MicrosoftPreview and follows the Robots Exclusion Protocol.
Microsoft Preview uses the user-agent token MicrosoftPreview. You can control it via robots.txt, meta tags (noai), or the emerging llms.txt standard. Robots.txt is voluntary; for hard enforcement, combine it with server-level IP blocking.

What happens if you block Microsoft Preview?

🔶 AI Visibility Trade-off - Blocking Microsoft Preview will not hurt Google or Bing rankings, but it can remove your content from AI search answers and assistant citations powered by this crawler. Block only if you have a deliberate reason.
Generally safe to allow; provides legitimate crawling value.

How to block Microsoft Preview with robots.txt

<code>User-agent: MicrosoftPreview</code> - Matching is case-insensitive. Robots.txt is fetched from the root of each subdomain separately.

Block completely (robots.txt)
User-agent: MicrosoftPreview Disallow: /
Allow all (robots.txt)
User-agent: MicrosoftPreview Allow: /
Block private only (robots.txt)
User-agent: MicrosoftPreview Disallow: /private/ Disallow: /api/ Disallow: /admin/ Allow: /
Nginx server block
# Nginx: Hard-block Microsoft Preview if ($http_user_agent ~* "MicrosoftPreview") { return 403 "Bot blocked"; }
Apache .htaccess
# Apache: Hard-block Microsoft Preview SetEnvIfNoCase User-Agent "MicrosoftPreview" bad_bot Order Allow,Deny Allow from all Deny from env=bad_bot
Meta robots tag
<meta name="robots" content="noindex, nofollow">
X-Robots-Tag header
X-Robots-Tag: noindex, nofollow

Is Microsoft Preview safe to allow?

Yes, Microsoft Preview is a safe and legitimate crawler operated by Microsoft. It follows the Robots Exclusion Protocol (RFC 9309) and can be controlled with standard robots.txt rules.
Verify by reverse-DNS lookup: legitimate Microsoft Preview requests resolve to Microsoft's domain.

What does Microsoft Preview do?

Understanding Microsoft Preview's purpose helps you decide whether to allow or block it.

  • Indexes web pages for AI-powered search answers
  • Surfaces your content as citations inside AI search results
  • Builds a knowledge index used to answer user questions
  • Allowing it can increase visibility in AI search
  • Respects robots.txt directives

Frequently Asked Questions

What is the official user-agent string for Microsoft Preview?
The official user-agent string for Microsoft Preview is: MicrosoftPreview. Use this exact string in robots.txt, Nginx, Apache, or Cloudflare firewall rules to target this bot. Matching in robots.txt is case-insensitive. Verify a request genuinely comes from Microsoft Preview by performing a reverse-DNS lookup on the source IP.
Is Microsoft Preview safe?
Yes, Microsoft Preview is a safe and legitimate crawler operated by Microsoft. It follows the Robots Exclusion Protocol (RFC 9309) and can be controlled with standard robots.txt rules.
Will blocking Microsoft Preview hurt my SEO?
🔶 AI Visibility Trade-off - Blocking Microsoft Preview will not hurt Google or Bing rankings, but it can remove your content from AI search answers and assistant citations powered by this crawler. Block only if you have a deliberate reason.
How do I block Microsoft Preview in robots.txt?
Add the following lines to your /robots.txt file:
User-agent: MicrosoftPreview
Disallow: /

This instructs Microsoft Preview not to crawl any path on your site. To block only specific sections, replace / with the path (e.g., Disallow: /blog/).
Does Microsoft Preview respect robots.txt?
Microsoft Preview is operated by Microsoft and is expected to fetch and parse /robots.txt before crawling, following RFC 9309. For hard enforcement, combine robots.txt with server-level IP or user-agent blocking.
How do I verify if Microsoft Preview is crawling my site?
Search your web server access logs for the string MicrosoftPreview (case-insensitive: grep -i "MicrosoftPreview" /var/log/nginx/access.log). Filter by user-agent in your log analytics tool (GoAccess, AWStats, etc.).

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