DuckAssistBot user agent
Operated by DuckDuckGo
DuckAssistBot is DuckDuckGo's crawler that fetches pages in real time to source answers for DuckAssist AI answers.
The DuckAssistBot bot at a glance
- DuckAssistBot is operated by DuckDuckGo and fetches a page when a person asks an AI assistant about it or shares its link.
- The robots.txt token for DuckAssistBot is DuckAssistBot.
- Blocking an AI assistant fetcher has no effect on search rankings.
- DuckAssistBot robots.txt support: Yes.
- Recommendation for Generative Engine Optimization (GEO): Allow.
What is DuckAssistBot?
DuckAssistBot reads pages to build DuckAssist answers. DuckDuckGo states the data is not used to train AI models.
DuckDuckGo states that blocking it does not affect organic rankings in DuckDuckGo search.
Should you block DuckAssistBot?
Allow DuckAssistBot unless it causes a measurable load problem.
| Effect on search rankings | Blocking an AI assistant fetcher has no effect on search rankings. |
|---|---|
| Effect on AI visibility | Blocking stops the assistant from reading your page when a user asks about it or pastes your link, so its answer falls back to other sources. |
| Follows robots.txt | Yes |
| Recommendation | Allow |
How to block or allow DuckAssistBot
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 DuckAssistBot is matched case-insensitively.
robots.txt: block
# Block DuckAssistBot
User-agent: DuckAssistBot
Disallow: /robots.txt: allow
# Allow DuckAssistBot
User-agent: DuckAssistBot
Allow: /robots.txt: partial
# Keep DuckAssistBot out of private areas only
User-agent: DuckAssistBot
Disallow: /wp-admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Allow: /Nginx
# Nginx: return 403 to DuckAssistBot
if ($http_user_agent ~* "(DuckAssistBot)") {
return 403;
}Apache
# Apache .htaccess: return 403 to DuckAssistBot
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (DuckAssistBot) [NC]
RewriteRule .* - [F,L]Cloudflare WAF
# Cloudflare > Security > WAF > Custom rule, action: Block
(http.user_agent contains "DuckAssistBot")How to verify real DuckAssistBot traffic
DuckDuckGo publishes the IP ranges that DuckAssistBot uses. A request with the DuckAssistBot user agent from an IP outside that list is an impersonator.
How to find DuckAssistBot in your server logs
Search the web server access log for the token. The command below counts DuckAssistBot requests per URL on Nginx or Apache.
grep -i "DuckAssistBot" 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.
DuckAssistBot user agent string
The full user agent DuckDuckGo publishes for DuckAssistBot. Version numbers such as Chrome/W.X.Y.Z change over time, so match the token, not the whole string.
DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html)DuckAssistBot FAQ
DuckAssistBot identifies itself with the robots.txt token "DuckAssistBot". A typical request header reads: DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html)
Yes. DuckDuckGo states that DuckAssistBot follows robots.txt rules written for the "DuckAssistBot" token.
Blocking an AI assistant fetcher has no effect on search rankings. Blocking stops the assistant from reading your page when a user asks about it or pastes your link, so its answer falls back to other sources.
Add two lines to the robots.txt file at the root of each domain and subdomain: "User-agent: DuckAssistBot" followed by "Disallow: /". The token is case-insensitive. Changes can take up to 24 hours to be picked up.
Yes. DuckDuckGo publishes the IP ranges DuckAssistBot uses. Check the request IP against that list; a matching user agent from any other IP is an impersonator.
Search your server access log for "DuckAssistBot", for example with: grep -i "DuckAssistBot" access.log. The AI Log File Analyzer by Justin Hà counts visits per AI bot from an uploaded log file.
Sources: DuckDuckGo 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.
