YandexAccessibilityBot
Yandex operates YandexAccessibilityBot, which downloads pages to check their accessibility for users. It sends up to 3 requests per second and ignores the Yandex Webmaster crawl-rate setting. Its robots.txt token is YandexAccessibilityBot; it may ignore User-agent: * rules, so name it directly. Verify it by reverse and forward DNS on a yandex.ru, yandex.net or yandex.com hostname.
Mozilla/5.0 (compatible; YandexAccessibilityBot/3.0; +http://yandex.com/bots)What YandexAccessibilityBot does
The robot arrives as "Mozilla/5.0 (compatible; YandexAccessibilityBot/3.0; +http://yandex.com/bots)". Yandex states it sends up to 3 requests to the site per second and ignores the crawl-rate setting in Yandex Webmaster, so lowering that setting will not slow it. Yandex's stated purpose is to download pages to check their accessibility for users. The documentation does not say which pages it selects or what it does with the result; a site owner sees page downloads at up to that rate.
Yandex's robot table marks this bot as not taking the general rules in robots.txt into account, so a site-wide User-agent: * disallow may not stop it. To restrict it, add a block that names its exact user agent, User-agent: YandexAccessibilityBot, followed by the Disallow lines you want applied. Blocking it stops the accessibility downloads and, because the robot has its own token, leaves YandexBot and the other Yandex robots unaffected. Yandex does not document what, if anything, a site loses in Yandex services when you block this robot.
Verification is the standard Yandex procedure. Take the request IP, run a reverse DNS lookup and check that the hostname ends in yandex.ru, yandex.net or yandex.com, then run a forward lookup on that hostname and confirm it returns the original IP. Yandex Webmaster also has an IP address check tool. Yandex publishes no IP range list for this robot, and its documentation does not mention JavaScript execution.
Operator note. Yandex lists it under 'Takes into account the General rules specified in robots.txt' as No, so it may ignore 'User-agent: *' rules. Restrict it with a directive naming its exact User-agent.
Controlling YandexAccessibilityBot with robots.txt
Use the token YandexAccessibilityBot in robots.txt. Yandex documents limits on how this bot applies robots.txt; see the operator note.
User-agent: YandexAccessibilityBot
Disallow: /User-agent: YandexAccessibilityBot
Allow: /Verifying a request is really YandexAccessibilityBot
Anyone can put YandexAccessibilityBot 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>Common questions
Why is YandexAccessibilityBot ignoring my crawl-rate setting?
Yandex documents this behaviour. The reference states the robot sends up to 3 requests to the site per second and ignores the crawl-rate setting in Yandex Webmaster. The only documented way to reduce its traffic is a robots.txt directive that names the robot's exact user agent.
Should I block YandexAccessibilityBot?
If the request rate is a problem, a robots.txt block that names User-agent: YandexAccessibilityBot stops it; a general User-agent: * rule may not, because Yandex says the robot may ignore general rules. Yandex does not document any consequence for Yandex search or Webmaster from blocking it, so the registry cannot state one.
How do I verify YandexAccessibilityBot?
Reverse DNS the request IP and check the hostname ends in yandex.ru, yandex.net or yandex.com, then forward-resolve that hostname and confirm it returns the same IP. Yandex Webmaster's IP address check tool does the same job. Yandex publishes no IP range list for this robot.
Sources
Every fact on this page was checked against Yandex's own documentation, listed below, and re-checked by a second reviewer before publication. Reviewed September 2026.
Related crawlers
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.