Quantcastbot
Audience analytics crawler for ad measurement and targeting
About this crawler
Quantcastbot is a web crawler identified by the regular-expression pattern Quantcastbot\/ in the User-Agent request header. It is categorised as advertising. Use the regex above to detect, log, allow, or block Quantcastbot traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
0.26%
Technical details
- Name
- Quantcastbot
- Pattern
Quantcastbot\/- Tags
- advertising
- Reference
- https://www.quantcast.com/bot
- Added
- 2026/04/17
- Instances
- 1 known sample(s)
Sample User-Agent strings
Quantcastbot/1.0 (+http://www.quantcast.com/bot)
Block this crawler
robots.txt — disallow Quantcastbot:
User-agent: Quantcastbot
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} Quantcastbot\/ [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "Quantcastbot\\/") {
return 403;
}
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