DuckAssistBot: what it is, and how to allow or block it in robots.txt

Key point. DuckAssistBot is DuckDuckGo's AI user fetcher. It fetches a page when a person asks the assistant to look at it; it is not an automatic crawler. It follows robots.txt.

DuckAssistBot at a glance

These are the facts our registry holds for DuckAssistBot, checked against DuckDuckGo's documentation on October 18, 2026.

VendorDuckDuckGo
Used byDuck.ai / DuckAssist
PurposeAI user fetch
TypeUser agent
Follows robots.txtYes; source: vendor's own crawler page, read October 18, 2026
Vendor documentationDuckDuckGo crawler page, checked October 18, 2026
Published IP rangesduckduckgo.com/duckassistbot.json

What is DuckAssistBot?

DuckAssistBot is DuckDuckGo's AI user fetcher. It fetches a page when a person asks the assistant to look at it; it is not an automatic crawler. Our registry notes: DuckDuckGo says the data is not used to train AI models and that disallowing DuckAssistBot in robots.txt opts a site out of its AI-assisted answers (after 72 hours).

Does DuckAssistBot follow robots.txt?

Yes, DuckAssistBot follows robots.txt: our registry records this from the vendor's own crawler page, read October 18, 2026.

A robots.txt rule records your request. It does not prove a crawler honours it, and firewall or CDN bot settings can refuse a crawler that robots.txt allows, so check those too.

How do I block DuckAssistBot in robots.txt?

Add a group that names DuckAssistBot and disallows the whole site:

User-agent: DuckAssistBot
Disallow: /

To keep it out of one folder only, disallow that path instead, for example Disallow: /private/.

How do I allow DuckAssistBot?

DuckAssistBot is allowed by default: if no group names it and no User-agent: * rule blocks it, it may read every page. A crawler obeys the most specific group that names it and falls back to User-agent: * only when no group names it (RFC 9309), so if a catch-all rule blocks crawlers, add a group for it:

User-agent: DuckAssistBot
Allow: /

How can I tell if a request really comes from DuckAssistBot?

Match the request's IP address against DuckDuckGo's published list, because user agents can be faked: https://duckduckgo.com/duckassistbot.json.

How often do startup websites block DuckAssistBot?

We have no figure for DuckAssistBot: it was not one of the crawlers our AI Crawler Access Report tracked. For the crawlers it did track, the headline figure is: “3 of 569 startup websites (0.5%; 95% interval 0.2% to 1.5%) block at least one AI search crawler (Elementera AI Crawler Access Report, October 2026).”

The method and the per-crawler table are in the AI Crawler Access Report.

How do I check whether my robots.txt blocks DuckAssistBot?

Read the group by hand: our free crawler checker covers 13 crawlers, and DuckAssistBot is not one of them yet.

  1. Open yoursite.com/robots.txt.
  2. Look for a User-agent: DuckAssistBot line. If there is one, only that group applies to DuckAssistBot.
  3. If there is none, the User-agent: * group applies.
  4. Within the group, the longest matching Allow or Disallow rule for a path wins.

Where can I see every AI crawler?

Our list of AI crawlers shows all 26 names in our registry, filtered by purpose. The same data is a free JSON download in our AI crawler registry.

Frequently asked questions

Three questions site owners ask about this name, each answered in one paragraph.

Should I block DuckAssistBot?

Only if you do not want DuckDuckGo's assistant to read your pages when a person asks it to. It follows robots.txt.

Does blocking DuckAssistBot affect other crawlers?

No. robots.txt groups are matched by name, so a group for DuckAssistBot applies only to DuckAssistBot.

How do I see whether DuckAssistBot visits my site?

Search your server or CDN logs for DuckAssistBot in the user agent. User agents can be faked, so check the request's IP address against DuckDuckGo's published list: https://duckduckgo.com/duckassistbot.json

Work with us

There are two ways to work with us. Teams that want the work done for them can use our managed AEO services: Book a call. Teams that want to see where they stand first can start with Lenz, our free analysis of how ChatGPT and Gemini answer their buyers' questions: Get your free AI visibility report.

How this page was made

A script builds this page from our AI crawler registry, the vendor crawler pages we read on October 18, 2026, and, for the blocking figures, the AI Crawler Access Report. Every sentence in quotation marks was checked against the vendor's page that day. Soroush Mehri reviewed the page, and Mojtaba Ebadi approved it for publication.

Sources