Other · Yandex
YandexDirectDyn user agent, IP ranges and robots.txt
YandexDirectDyn is Yandex's other. It identifies itself with the YandexDirectDyn user-agent token, applies robots.txt only in part, per its operator, and can be verified by reverse DNS (yandex.ru, yandex.net, yandex.com).
- Operator
- Yandex
- Reviewed
- September 2026
- Sources
- 1
- Operator
- Yandex
- User-agent token
- YandexDirectDyn
- Purpose
- Other
- robots.txt token
- YandexDirectDyn
- Honors robots.txt
- Partially, see notes
- Published IP ranges
- No official range file
- Verification
- Reverse DNS lookup on the requesting IP must return a host ending in yandex.ru, yandex.net or yandex.com, and a forward DNS lookup of that host must return the same IP. Yandex Webmaster also provides an IP address check tool.
- Reverse DNS suffix
- yandex.ru, yandex.net, yandex.com
- Full user-agent example
- Mozilla/5.0 (compatible; YandexDirectDyn/1.0; +http://yandex.com/bots)
Block or allow YandexDirectDyn in robots.txt
User-agent: YandexDirectDyn
Disallow: /User-agent: YandexDirectDyn
Allow: /Verify a request is really YandexDirectDyn
Anyone can put YandexDirectDyn in a User-Agent header. Reverse DNS lookup on the requesting IP must return a host ending in yandex.ru, yandex.net or yandex.com, and a forward DNS lookup of that host must return the same IP. Yandex Webmaster also provides an IP address check tool.
host <request-ip>
# expect a hostname ending in yandex.ru, yandex.net, yandex.com
host <that-hostname>
# expect it to resolve back to <request-ip>What YandexDirectDyn does
YandexDirectDyn is a Yandex agent whose documented purpose is generating dynamic banners. It has its own YandexDirectDyn robots.txt token, but Yandex says general robots.txt rules do not apply to it. Yandex publishes no IP list; verify requests by reverse DNS to a hostname ending in yandex.ru, yandex.net or yandex.com, confirmed with a forward lookup.
Requests from this agent carry the user-agent Mozilla/5.0 (compatible; YandexDirectDyn/1.0; +http://yandex.com/bots). Yandex describes its purpose as generating dynamic banners and documents nothing more about what the agent fetches or how often it visits. The documented purpose is banner generation; Yandex does not describe the agent as part of search indexing, so a site owner who sees it in logs should read it as a banner-generation fetch. Yandex does not say whether the agent executes JavaScript.
Control works through the YandexDirectDyn token. Yandex says general robots.txt rules do not apply to this agent, so a group naming YandexDirectDyn is the documented way to stop it. Blocking it prevents whatever fetches Yandex makes for dynamic banner generation, and the operator documents no other consequence, including none for search visibility. Allowing it changes nothing Yandex describes beyond letting those fetches happen. Yandex publishes no IP range list for this agent, so verification is by reverse DNS with a forward lookup.
Operator note. It does not take into account the general rules in robots.txt.
Common questions
- Should I block YandexDirectDyn?
- Yandex gives you little to decide on. Its only stated purpose is generating dynamic banners, and Yandex documents no consequence of blocking it for search indexing or anything else. If you do block it, write a rule for the YandexDirectDyn token, because Yandex says general robots.txt rules do not apply to this agent.
- How do I verify YandexDirectDyn?
- Do a reverse DNS lookup on the requesting IP and confirm the hostname ends in yandex.ru, yandex.net or yandex.com, then resolve that hostname forward and check it returns the same IP. Yandex also has an IP address check tool in Yandex Webmaster. Yandex publishes no IP range list for this agent.
- What does YandexDirectDyn fetch from my site?
- Yandex's documentation does not say. The robot page lists the agent's purpose as generating dynamic banners and gives its user-agent string, but it does not describe which URLs the agent requests or whether it executes JavaScript.
Sources
The operator documentation used for this entry. Recorded review date September 2026; consult the linked pages for current policy and compare them with this dated snapshot.
This registry documents how operators describe their own bots so site owners can identify and control them. It does not publish third-party IP lists or guess at undocumented behaviour. To see how your own site responds to automated visitors, the bot detection scanner reads a URL's live response and names the protection it finds.