DuckAssistBot
DuckDuckGo assistant bot for web crawling and search
About this crawler
DuckAssistBot is a web crawler identified by the regular-expression pattern DuckAssistBot in the User-Agent request header. It is categorised as search-engine, ai-fetcher. Use the regex above to detect, log, allow, or block DuckAssistBot traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
2.2%
Technical details
- Name
- DuckAssistBot
- Pattern
DuckAssistBot- Tags
- search-engine, ai-fetcher
- Reference
- https://duckduckgo.com/duckduckgo-help-pages/results/duckassistbot
- Added
- 2026/04/07
- rDNS suffixes
.duckduckgo.com- Instances
- 1 known sample(s)
rDNS verification (FCrDNS)
Verify a request is genuinely DuckAssistBot with forward-confirmed reverse DNS: the client IP's PTR record must end in one of the suffixes below and a forward A/AAAA lookup of that hostname must return the same IP. UA strings alone are spoofable; FCrDNS is not.
.duckduckgo.com
Sample User-Agent strings
DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html)
Block this crawler
robots.txt — disallow DuckAssistBot:
User-agent: DuckAssistBot
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} DuckAssistBot [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "DuckAssistBot") {
return 403;
}
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