Glossary
DuckAssistBot DuckDuckGo's crawler for cited AI answers.
The bot that decides whether your pages can be a source in DuckDuckGo's AI-assisted answers. Prefer's crawler guides cover the trade-off: it is an answer crawler, not a training crawler, and blocking it leaves your normal rankings alone.
DuckAssistBot is DuckDuckGo's crawler that fetches pages in real time for its cited AI-assisted answers, and is not used to train AI models. Prefer's robots.txt guides show how to keep it allowed.
Key facts
At a glance.
The entity facts an assistant lifts first, each from DuckDuckGo's own help pages.
- Operator
- DuckDuckGo · duckduckgo.com
- Type
- Real-time crawler for AI-assisted answers
- User agent token
- DuckAssistBot
- Full UA string
- DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html)
- Respects robots.txt
- Yes. A block takes effect after 72 hours
- IP ranges
- Published at duckduckgo.com/duckassistbot.json
- Used for AI training
- No. DuckDuckGo says the data is not used in any way to train AI models
- Affects AI answers
- Yes. Blocking opts you out as a source for AI-assisted answers
- Affects organic rankings
- No, per DuckDuckGo
- First announced
- Not documented
How it works
What happens when DuckAssistBot visits.
Three steps. Unlike a training crawler, DuckAssistBot fetches for an answer, so the visit sits right before a possible citation.
- 01
Reads robots.txt
DuckDuckGo lets publishers opt out by disallowing the DuckAssistBot user agent in robots.txt. Once the file changes, DuckDuckGo says the block takes effect after 72 hours.
- 02
Fetches pages in real time
DuckDuckGo describes it as a crawler that crawls pages in real time for its AI-assisted answers.
- 03
Sources a cited answer
The fetched content is used to write AI-assisted answers, which DuckDuckGo says prominently cite their sources. It is not used in any way to train AI models.
The DuckDuckGo crawler family
DuckAssistBot is one of two. They do different jobs.
Each has its own token, so each can be allowed or blocked on its own.
Purpose, what blocking it changes, and whether it affects AI-assisted answers.
| Bot | Purpose | Blocking it means | Affects AI answers |
|---|---|---|---|
DuckAssistBotThis term | Crawls pages in real time for DuckDuckGo's AI-assisted answers, which cite their sources. Not used to train AI models. | You opt out of being a potential source for AI-assisted answers, after 72 hours. Organic rankings are unaffected. | ✓ Yes |
DuckDuckBot | DuckDuckGo's web crawler. Its user agent appears as DuckDuckBot/1.1; (+http://duckduckgo.com/duckduckbot.html) and it respects robots rules. | Not documented for AI answers. | ✕ Not documented |
Why it matters for AEO
Allow or block: the decision in one sentence.
Should you block DuckAssistBot?
For a brand that wants AI visibility, no, and Prefer's crawler guides treat it like any answer-time crawler. DuckAssistBot only fetches pages to source cited AI-assisted answers, DuckDuckGo says the data is not used to train AI models, and blocking it does not touch your organic rankings, so the only thing a block removes is your chance to be cited.
- You want to be a cited source in DuckDuckGo's AI-assisted answers
- You allow other answer crawlers such as OAI-SearchBot and PerplexityBot
- Your worry is training use, which DuckDuckGo says this bot does not do
- You do not want any AI-written summaries built from your pages
- The content is paid or licensed and should not be quoted in answers
- You block by path, so public pages can still be cited
DuckDuckGo says blocking does not affect organic rankings, so this decision is only about the AI-assisted answers.
Allow or block it
Three robots.txt patterns that cover most cases.
Each pattern names the DuckAssistBot token explicitly. A wildcard Disallow catches it too.
robots.txtCopy the pattern that matches your decision above.
User-agent: DuckAssistBot
Allow: /
User-agent: DuckDuckBot
Allow: /
The pattern most brands want: a possible source in AI-assisted answers, normal search unchanged.
- Check for a wildcard firstA User-agent: * group with Disallow: / already blocks DuckAssistBot. A group that names it overrides the wildcard for that bot only.
- Changes take 72 hoursDuckDuckGo says a new disallow takes effect after 72 hours, so do not expect the next visit to respect it.
- Questions go to DuckDuckGoDuckDuckGo lists [email protected] as the contact for crawler questions.
# Opts out of AI-assisted answers only.
# DuckDuckGo says organic rankings are not affected.
User-agent: DuckAssistBot
Disallow: /
User-agent: DuckDuckBot
Allow: /
Out of the AI-assisted answers, still in DuckDuckGo search results. Takes effect after 72 hours.
- Check for a wildcard firstA User-agent: * group with Disallow: / already blocks DuckAssistBot. A group that names it overrides the wildcard for that bot only.
- Changes take 72 hoursDuckDuckGo says a new disallow takes effect after 72 hours, so do not expect the next visit to respect it.
- Questions go to DuckDuckGoDuckDuckGo lists [email protected] as the contact for crawler questions.
User-agent: DuckAssistBot
Allow: /
Disallow: /research/
Disallow: /members/
Keep public pages citable, protect the paid archive.
- Check for a wildcard firstA User-agent: * group with Disallow: / already blocks DuckAssistBot. A group that names it overrides the wildcard for that bot only.
- Changes take 72 hoursDuckDuckGo says a new disallow takes effect after 72 hours, so do not expect the next visit to respect it.
- Questions go to DuckDuckGoDuckDuckGo lists [email protected] as the contact for crawler questions.
Verify a visit
How to confirm it was really DuckAssistBot.
Any script can claim the DuckAssistBot user agent. DuckDuckGo documents the IP addresses it crawls from.
- 01
Match the user agent
Look for the DuckAssistBot token in the user agent field. The full string is DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html).
- 02
Match the IP address
Compare the request IP against the list DuckDuckGo publishes at duckduckgo.com/duckassistbot.json. The help page shows a shorter inline list; the JSON file is the fuller one.
203.0.113.42 - - [01/Oct/2026:09:14:07 +0000] "GET /pricing/ HTTP/1.1" 200 18422 "-" "DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html)"In context
The term in a sentence.
01"We allow DuckAssistBot alongside OAI-SearchBot and PerplexityBot, because DuckDuckGo says it does not train on our pages and only sources cited answers."
02"Legal asked us to keep the members archive out of AI summaries, so we disallowed DuckAssistBot on that path only."
Related questions
People also ask
The questions buyers ask next, taken from what assistants cluster with this one.
Is DuckAssistBot a training crawler?
No. DuckDuckGo says DuckAssistBot data is not used in any way to train AI models, and Prefer's crawler guides class it as an answer-time crawler for that reason. It fetches pages in real time to source cited AI-assisted answers.
See the crawler comparison →What is the DuckAssistBot user agent string?
At the checked-on date DuckDuckGo publishes it as DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html). Prefer's robots.txt guides use the token on its own, DuckAssistBot, in the User-agent line.
How long does a DuckAssistBot block take to work?
DuckDuckGo says the change takes effect after 72 hours. Prefer's advice for any robots.txt change applies here too: test the file before you publish it, because a wildcard rule can block more bots than you meant to.
Questions
Asked plainly.
What does DuckAssistBot do?
DuckAssistBot is DuckDuckGo's crawler that fetches pages in real time for its AI-assisted answers, which cite their sources. Prefer treats it like the other answer-time crawlers in its guides: it decides whether you can be a cited source. DuckDuckGo says the data is not used in any way to train AI models.
How do I block or allow DuckAssistBot?
Prefer's free robots.txt generator builds the groups for the major AI crawlers, and you add a 'User-agent: DuckAssistBot' group to that file by hand. Use 'Disallow: /' to opt out or 'Allow: /' to stay in. DuckDuckGo says a block takes effect after 72 hours.
Does blocking DuckAssistBot affect my DuckDuckGo rankings?
No. Prefer's crawler guides point to DuckDuckGo's own wording: opting out of DuckAssistBot does not impact organic search rankings and will not affect whether your site appears in its search results. DuckDuckGo's general web crawler is a separate bot, DuckDuckBot, so a block only removes you as a potential source for the AI-assisted answers.
Does DuckAssistBot use my content to train AI?
No, according to DuckDuckGo, which says DuckAssistBot data is not used in any way to train AI models. Prefer separates answer-time crawlers like this one from training crawlers like GPTBot for exactly that reason: the allow or block trade-off is different.
Sources
Where these facts come from.
Every fact on this page traces to one of these. Where DuckDuckGo does not document something, the page says so rather than guessing.
- 01 DuckDuckGo, Is DuckAssistBot related to DuckDuckGo? The help page for DuckAssistBot: purpose, user agent, robots.txt opt-out, the 72-hour delay and the rankings note. Vendor docs 1 Oct 2026
- 02 DuckDuckGo, DuckAssistBot IP list The published IP list used for the verification step above. Vendor data 1 Oct 2026
- 03 DuckDuckGo, DuckDuckBot The help page for DuckDuckGo's web crawler, used in the family table. Vendor docs 1 Oct 2026
- 04 Robots Exclusion Protocol, RFC 9309 The standard that defines how user-agent tokens, Allow and Disallow rules are interpreted. Standard 1 Oct 2026
DuckAssistBot, DuckDuckBot and DuckDuckGo are trademarks of DuckDuckGo. Prefer is not affiliated with, endorsed by or sponsored by DuckDuckGo. This entry reflects public documentation at the dates shown. Something wrong here? Tell us and we will fix it →
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