DuckDuckBot

search-engine DuckDuckBot

DuckDuckGo search engine web crawler bot

About this crawler

DuckDuckBot is a web crawler identified by the regular-expression pattern DuckDuckBot in the User-Agent request header. It is categorised as search-engine. Use the regex above to detect, log, allow, or block DuckDuckBot traffic in your web server, CDN edge rules, or robots.txt.

Block-rate · top 25k sites

0.52%
latest snapshot
2026-06-04
matched key: DuckDuckBot
2026-05-012026-06-040.60%

Technical details

Name
DuckDuckBot
Pattern
DuckDuckBot
Tags
search-engine
Reference
https://duckduckgo.com/duckduckgo-help-pages/results/duckduckbot
Added
2012/09/19
rDNS suffixes
.duckduckgo.com
Instances
4 known sample(s)

rDNS verification (FCrDNS)

Verify a request is genuinely DuckDuckBot 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.

Sample User-Agent strings

DuckDuckBot/1.0; (+http://duckduckgo.com/duckduckbot.html)
DuckDuckBot/1.1; (+http://duckduckgo.com/duckduckbot.html)
Mozilla/5.0 (compatible; DuckDuckBot-Https/1.1; https://duckduckgo.com/duckduckbot)
'Mozilla/5.0 (compatible; DuckDuckBot-Https/1.1; https://duckduckgo.com/duckduckbot)'

Block this crawler

robots.txt — disallow DuckDuckBot:

User-agent: DuckDuckBot Disallow: /

Apache .htaccess — return 403:

RewriteEngine On RewriteCond %{HTTP_USER_AGENT} DuckDuckBot [NC] RewriteRule .* - [F,L]

Nginx — return 403 inside a server block:

if ($http_user_agent ~* "DuckDuckBot") { return 403; }
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