MicrosoftPreview user agent
Operated by Microsoft
MicrosoftPreview is the Microsoft fetcher that generates page snapshots and previews for Microsoft products.
The MicrosoftPreview bot at a glance
- MicrosoftPreview is operated by Microsoft and reads page titles, descriptions and images to build link previews.
- The robots.txt token for MicrosoftPreview is MicrosoftPreview.
- Blocking a social preview bot has no effect on search rankings.
- MicrosoftPreview robots.txt support: Yes.
- Recommendation for Generative Engine Optimization (GEO): Allow.
What is MicrosoftPreview?
MicrosoftPreview has desktop and mobile variants and creates page snapshots used across Microsoft products.
Bing documents it on the same page as Bingbot.
Should you block MicrosoftPreview?
Allow MicrosoftPreview unless it causes a measurable load problem.
| Effect on search rankings | Blocking a social preview bot has no effect on search rankings. |
|---|---|
| Effect on AI visibility | No direct effect on AI answers, but shared links lose their title, image and description, which usually lowers clicks from social and chat apps. |
| Follows robots.txt | Yes |
| Recommendation | Allow |
How to block or allow MicrosoftPreview
Put the robots.txt rule in the file at the root of every domain and subdomain, for example https://example.com/robots.txt. The token MicrosoftPreview is matched case-insensitively.
robots.txt: block
# Block MicrosoftPreview
User-agent: MicrosoftPreview
Disallow: /robots.txt: allow
# Allow MicrosoftPreview
User-agent: MicrosoftPreview
Allow: /robots.txt: partial
# Keep MicrosoftPreview out of private areas only
User-agent: MicrosoftPreview
Disallow: /wp-admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Allow: /Nginx
# Nginx: return 403 to MicrosoftPreview
if ($http_user_agent ~* "(MicrosoftPreview)") {
return 403;
}Apache
# Apache .htaccess: return 403 to MicrosoftPreview
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (MicrosoftPreview) [NC]
RewriteRule .* - [F,L]Cloudflare WAF
# Cloudflare > Security > WAF > Custom rule, action: Block
(http.user_agent contains "MicrosoftPreview")How to verify real MicrosoftPreview traffic
Microsoft publishes no IP list or reverse DNS pattern for MicrosoftPreview, so the user agent cannot be verified. Anyone can send the same string. Rate-limit unusual volume instead of trusting the name.
How to find MicrosoftPreview in your server logs
Search the web server access log for the token. The command below counts MicrosoftPreview requests per URL on Nginx or Apache.
grep -i "MicrosoftPreview" access.log | awk '{print $7}' | sort | uniq -c | sort -rn | head -20For a full report per AI bot, upload the log to the AI Log File Analyzer, a free tool by Justin Hà.
MicrosoftPreview user agent string
The full user agent Microsoft publishes for MicrosoftPreview. Version numbers such as Chrome/W.X.Y.Z change over time, so match the token, not the whole string.
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; MicrosoftPreview/2.0; +https://aka.ms/MicrosoftPreview) Chrome/W.X.Y.Z Safari/537.36MicrosoftPreview FAQ
MicrosoftPreview identifies itself with the robots.txt token "MicrosoftPreview". A typical request header reads: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; MicrosoftPreview/2.0; +https://aka.ms/MicrosoftPreview) Chrome/W.X.Y.Z Safari/537.36
Yes. Microsoft states that MicrosoftPreview follows robots.txt rules written for the "MicrosoftPreview" token.
Blocking a social preview bot has no effect on search rankings. No direct effect on AI answers, but shared links lose their title, image and description, which usually lowers clicks from social and chat apps.
Add two lines to the robots.txt file at the root of each domain and subdomain: "User-agent: MicrosoftPreview" followed by "Disallow: /". The token is case-insensitive. Changes can take up to 24 hours to be picked up.
Not reliably. Microsoft publishes no IP list or reverse DNS pattern for MicrosoftPreview, so anyone can send the same user agent. Rate-limit unusual volume instead of trusting the name.
Search your server access log for "MicrosoftPreview", for example with: grep -i "MicrosoftPreview" access.log. The AI Log File Analyzer by Justin Hà counts visits per AI bot from an uploaded log file.
Sources: Microsoft crawler documentation. Last reviewed by Justin Hà.
See which of these bots actually reach your website
The AI Log File Analyzer by Justin Hà counts visits from GPTBot, ClaudeBot, PerplexityBot and other AI crawlers in your server log, for free. The GEO Technical Package sets up robots.txt, llms.txt and crawler access for AI search.
