Should you block DuckAssistBot? DuckDuckGo's AI-answer bot
DuckAssistBot is operated by DuckDuckGo. It crawls pages in real time for DuckDuckGo's AI-assisted answers, which cite their sources. DuckDuckGo says the data is not used to train AI models.
Who should block DuckAssistBot, and who should not?
Block it if you do not want DuckDuckGo's AI answers to summarize your text, and you accept losing the source link those answers carry. DuckDuckGo's help page makes this a clean trade: the opt-out leaves organic rankings alone and the data is not used for training, so a block gives up AI-answer visibility. Sites that want DuckDuckGo traffic should usually leave it open, because the answers cite their sources. Wait three days before checking whether a block worked.
The verified facts
| User-agent token | DuckAssistBot/1.2 |
|---|---|
| Full user agent in logs | DuckAssistBot/1.2; (+http://duckduckgo.com/duckassistbot.html) |
| Operator | DuckDuckGo |
| Purpose | Search and AI-search indexers |
| Honors robots.txt | Yes, per the operator's documentation. |
| Published IP ranges | duckduckgo.com/duckassistbot.json |
What does DuckDuckGo’s documentation add?
- A robots.txt block takes effect after 72 hours, according to DuckDuckGo. Opt-out problems go to crawling@duckduckgo.com.
- DuckDuckGo says opting out does not affect organic rankings or whether a site appears in its search results.
- It crawls from the same addresses as DuckDuckBot: on 2026-09-26 the two published IP files were identical. Separate the two by user-agent token, not by IP.
How do you block DuckAssistBot?
Add this to your robots.txt:
User-agent: DuckAssistBot
Disallow: /Once you give a crawler its own group, it stops reading your User-agent: * rules, so run the whole file through the AI crawler robots.txt tester before you deploy it.
How do you tell a real DuckAssistBot request from a fake one?
A user-agent match proves nothing, since any client can send DuckAssistBot/1.2. Check the IP against the published range file above, re-fetched on a schedule. A request that fails is not DuckDuckGo. The log verification guide has a script for the IP check and a worked reverse-DNS example, or paste the IP into the AI crawler IP verifier, which runs these checks against DuckDuckGo’s current data.
What does blocking DuckAssistBot cost you?
Content excluded from DuckDuckGo AI-assisted answers; does not affect organic search ranking.
What else does DuckDuckGo document?
DuckDuckGo also documents DuckDuckBot, which has its own robots.txt token. How DuckDuckGo’s crawlers fit together.
Which crawlers in the same group should you decide on at the same time?
A robots.txt group for DuckAssistBot does nothing to crawlers with other tokens. In the same group, the directory also covers Meta-WebIndexer (Meta), Amzn-SearchBot (Amazon), YouBot (You.com), Diffbot (Diffbot), PetalBot (Huawei) and MistralAI-Index (Mistral), each with its own token and its own documented cost of blocking.