Published on 2025-08-07T06:18:08Z

DuckAssistBot

DuckAssistBot is an AI assistant bot from the privacy-focused search engine DuckDuckGo. It powers the DuckAssist feature, which generates real-time AI answers to user searches. Unlike traditional crawlers, DuckAssistBot operates on-demand, fetching content from trusted sources like Wikipedia and Britannica only when a user's query triggers the feature. This targeted approach provides users with instant, sourced answers while minimizing data collection.

What is DuckAssistBot?

DuckAssistBot is the specialized AI assistant bot for the search engine DuckDuckGo, powering its DuckAssist feature. It is a user-agent that fetches content from a curated list of trusted sources (primarily Wikipedia and Britannica) to generate instant AI-powered answers to search queries. Unlike a traditional crawler, DuckAssistBot is on-demand, activating only when a user's search triggers the feature. It identifies itself in server logs with the user-agent string DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html). This bot is a key component in DuckDuckGo's system for providing quick, reliable answers without broad, continuous web indexing.

Why is DuckAssistBot crawling my site?

The presence of DuckAssistBot in your logs means that a DuckDuckGo user has submitted a search query that triggered the DuckAssist feature, and your site (most likely Wikipedia or Britannica) was identified as a source for the answer. It does not crawl sites autonomously. The frequency of visits is entirely dependent on user search behavior. This on-demand model aligns with DuckDuckGo's privacy-focused mission by ensuring that external websites are accessed only to fulfill a specific user request.

What is the purpose of DuckAssistBot?

The primary purpose of DuckAssistBot is to support DuckDuckGo's DuckAssist feature by providing instant, sourced answers directly on the search results page. When a user asks a question, the bot retrieves relevant passages from trusted sources. These passages are then processed by AI models to generate a concise, conversational answer that appears above the traditional search results, complete with source links for verification. This benefits users by providing immediate, factual answers while maintaining transparency. For the websites it uses as sources, it can drive visibility and traffic.

How do I block DuckAssistBot?

To prevent DuckAssistBot from accessing your website, you can add a disallow rule to your robots.txt file. This is the standard method for managing crawler access.

Add the following lines to your robots.txt file to block DuckAssistBot:

User-agent: DuckAssistBot
Disallow: /

How to verify the authenticity of the user-agent operated by DuckDuckGo?

Reverse IP lookup technique

To verify user-agent authenticity, you can use host linux command two times with the IP address of the requester.
  1. > host IPAddressOfRequest
    This command returns the reverse lookup hostname (e.g., 4.4.8.8.in-addr.arpa.). 
  2. > host ReverseDNSFromTheOutputOfFirstRequest
If the output matches the original IP address and the domain is associated with a trusted operator (e.g., DuckDuckGo), the user-agent can be considered legitimate.

IP list lookup technique

Some operators provide a public list of IP addresses used by their crawlers. This list can be cross-referenced to verify a user-agent's authenticity. However, both operators and website owners may find it challenging to maintain an up-to-date list, so use this method with caution and in conjunction with other verification techniques.