What is YandexAccessibilityBot? Yandex's service crawler
YandexAccessibilityBot checks that pages can be reached by users. Yandex says it makes about three requests a second at most and ignores the crawl-rate setting in Yandex Webmaster.
2 of the 1662 major websites we measure block YandexAccessibilityBot in robots.txt (0%). 3 of those sites name it directly in their robots.txt; the rest are covered by a wildcard rule.
Key facts
| Fact | Detail |
|---|---|
| Operator | Yandex |
| Used for | Yandex |
| Type | Site service. Runs a check or a tool for its operator, such as testing tools, screenshots or availability. It isn't counted in the AI crawler figures. |
| robots.txt token | YandexAccessibilityBot |
| Operator's documentation | Read it here |
What blocking YandexAccessibilityBot does
Yandex says this robot does not take the general robots.txt rules into account, including a User-agent: Yandex group; only a group that names it applies. The figures below count it that way.
How to allow or block YandexAccessibilityBot
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: YandexAccessibilityBot Disallow: /
User-agent: YandexAccessibilityBot Allow: /
YandexAccessibilityBot user agent string
Yandex's page doesn't list a full string, so look for YandexAccessibilityBot in the user agent field of your logs.
How to verify a request is really YandexAccessibilityBot
Anyone can put a crawler's name in a user agent string, so the name alone proves nothing. We did not find a published IP list or reverse DNS rule from Yandex.
How to whitelist YandexAccessibilityBot 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 in the user agent. Keep the rule narrow, because anyone can copy a name.
- Check your server logs for a 200 response from YandexAccessibilityBot afterwards.
On Cloudflare, also check AI Crawler and Agent access policies, which can block search, agent and training traffic across a site.
Why YandexAccessibilityBot 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 ~* "YandexAccessibilityBot") {
return 403;
}Who blocks YandexAccessibilityBot, by sector
| Sector | Sites measured | Blocking | Share |
|---|---|---|---|
| News publishers | 182 | 2 | 1% |
| AI companies | 128 | 0 | 0% |
| Developer references | 159 | 0 | 0% |
| E-commerce and retail | 92 | 0 | 0% |
| Finance and business media | 94 | 0 | 0% |
| Government and institutions | 98 | 0 | 0% |
| Health publishers | 88 | 0 | 0% |
| Hosting and infrastructure | 98 | 0 | 0% |
| Reference and research | 114 | 0 | 0% |
| SaaS platforms | 196 | 0 | 0% |
| SEO and marketing tools | 86 | 0 | 0% |
| Social and media platforms | 115 | 0 | 0% |
| Technology media | 126 | 0 | 0% |
| Travel | 86 | 0 | 0% |
Sites blocking YandexAccessibilityBot
Sites that allow YandexAccessibilityBot by name
Other Yandex crawlers
YandexBot (search indexing), YandexImages (image indexing), YandexVideo (video indexing), YandexMedia (multimedia indexing), YandexBlogs (blog search), YandexMarket (Yandex Market), YandexAdNet (advertising network), YandexOntoDB (information cards), YandexPagechecker (structured data checks), YandexSitelinks (sitelinks checks), YandexSpravBot (Yandex Business), YandexVertis (search verticals), YandexVerticals (classifieds verticals), YandexWebmaster (Yandex Webmaster), YandexImageResizer (mobile images), YandexCalendar (calendar files on request), YandexCheckBot (availability checks), YandexDirectDyn (dynamic ad banners), YandexDirect (ad matching), YandexFavicons (favicons), YandexFeed (submitted structured data), YandexMobileBot (mobile layout checks), YandexMobileScreenShotBot (mobile screenshots), YandexOntoDBAPI (information card data), YandexPartner (partner sites), YandexRCA (previews), YandexSearchShop (product catalogues on request), YandexTracker (Yandex Tracker), YandexUserproxy (user actions), YandexVideoParser (video indexing), YandexScreenshotBot (screenshots).
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. "YandexAccessibilityBot block rate across major websites." Measured 12 November 2026. https://www.indexhalo.com/ai-crawlers/yandexaccessibilitybot/
<a href="https://www.indexhalo.com/ai-crawlers/yandexaccessibilitybot/">YandexAccessibilityBot block rate across major websites, IndexHalo</a>