What is DuckDuckBot? DuckDuckGo's search crawler
DuckDuckBot is DuckDuckGo's web crawler, which DuckDuckGo says it uses to keep improving its search results.
12 of the 1664 major websites we measure block DuckDuckBot in robots.txt (1%). 40 of those sites name it directly in their robots.txt; the rest are covered by a wildcard rule.
Key facts
| Fact | Detail |
|---|---|
| Operator | DuckDuckGo |
| Used for | DuckDuckGo search |
| Type | Search engine. Builds a search engine's index. Listed here because people look it up beside AI crawlers. It isn't counted in the AI crawler figures. |
| robots.txt token | DuckDuckBot |
| Operator's documentation | Read it here |
What blocking DuckDuckBot does
DuckDuckGo says DuckDuckBot follows the robots.txt standard. It is a different agent from DuckAssistBot, which fetches pages for DuckDuckGo's AI answers.
How to allow or block DuckDuckBot
Add one of these groups to the robots.txt file at the root of your domain. It is a stated preference that well-behaved crawlers read, not an enforcement mechanism.
User-agent: DuckDuckBot Disallow: /
User-agent: DuckDuckBot Allow: /
DuckDuckBot user agent string
The string DuckDuckGo documents. Version numbers can change, so match on the name.
DuckDuckBot/1.1; (+http://duckduckgo.com/duckduckbot.html)
How to verify a request is really DuckDuckBot
Anyone can put a crawler's name in a user agent string, so the name alone proves nothing. DuckDuckGo publishes the addresses DuckDuckBot uses: duckduckgo.com/duckduckbot.json. Check a request's source address against that list.
How to whitelist DuckDuckBot in a firewall or CDN
robots.txt only states a preference. A firewall, CDN or bot protection service can still refuse the request, and the crawler then gets an error even though robots.txt allows it.
- Check that no group in your robots.txt blocks it, using the rule above.
- Add an allow rule in your firewall or CDN that matches the name and the published IP addresses. Keep the rule narrow, because anyone can copy a name.
- Check your server logs for a 200 response from DuckDuckBot afterwards.
On Cloudflare, also check AI Crawler and Agent access policies, which can block search, agent and training traffic across a site.
Why DuckDuckBot gets a 403 or 405 error
A 403 means the server refused the request, which usually points to a firewall or bot rule. A 405 means the server refused the request's method, so check any rule that only permits certain methods. A crawler that obeys robots.txt won't request a page it is told to avoid, so an error in your logs points to your server's configuration. To stop it deliberately at the server, this nginx rule returns a 403:
if ($http_user_agent ~* "DuckDuckBot") {
return 403;
}Who blocks DuckDuckBot, by sector
| Sector | Sites measured | Blocking | Share |
|---|---|---|---|
| Social and media platforms | 115 | 3 | 3% |
| Reference and research | 114 | 2 | 2% |
| AI companies | 128 | 1 | 1% |
| E-commerce and retail | 92 | 1 | 1% |
| Finance and business media | 94 | 1 | 1% |
| Hosting and infrastructure | 98 | 1 | 1% |
| News publishers | 182 | 2 | 1% |
| SaaS platforms | 196 | 1 | 1% |
| Developer references | 160 | 0 | 0% |
| Government and institutions | 98 | 0 | 0% |
| Health publishers | 89 | 0 | 0% |
| SEO and marketing tools | 86 | 0 | 0% |
| Technology media | 126 | 0 | 0% |
| Travel | 86 | 0 | 0% |
Sites blocking DuckDuckBot
afterpay.com, distill.pub, fortinet.com, instacart.com, linguee.com, magento.com, netflix.com, reddit.com, reuters.com, todayonline.com, wordreference.com, x.com.
Sites that allow DuckDuckBot by name
academia.edu, amplitude.com, barrons.com, bestbuy.com, binance.com, consilium.europa.eu, devclass.com, disneyplus.com, eluniversal.com.mx, facebook.com, fastcompany.com, flickr.com, glean.com, golem.de, hackernoon.com, heygen.com, ign.com, illinois.gov, imdb.com, inc.com, influxdata.com, instagram.com, lobste.rs, marketwatch.com, meta.ai, news.com.au, pinterest.com, poe.com, posthog.com, resemble.ai, salon.com, santander.co.uk, sap.com, sciencedirect.com, theregister.com, thesun.co.uk, thetimes.co.uk, threads.net, wsj.com, zeit.de.
Other DuckDuckGo crawlers
DuckAssistBot (on-demand fetch).
See all 36 AI crawlers, the rule change log or the full study. Being reachable is only the first step: how AI search engines choose what to cite covers the rest.
Cite this data
You are welcome to quote or republish these figures. Please credit IndexHalo with a link to this page (CC BY 4.0). All our datasets are on the data page.
IndexHalo. "DuckDuckBot block rate across major websites." Measured 12 November 2026. https://www.indexhalo.com/ai-crawlers/duckduckbot/
<a href="https://www.indexhalo.com/ai-crawlers/duckduckbot/">DuckDuckBot block rate across major websites, IndexHalo</a>