Safe Official docs Search Engines

YandexAdditionalBot

Operated by Yandex

Quick Facts

User-Agent:
YandexAdditionalBot
Category:
Search Engines
Operator:
Yandex
Safety:
Safe
Blocking Impact:
Critical - Blocking removes you from search results
SEO Impact Score:
10/10
Official docs:
yandex.com

Confirmed by the operator

Yandex names YandexAdditionalBot on its own documentation page, linked above. The token, purpose and robots.txt behaviour on this profile come from that page, re-checked on September 22, 2026.

What is YandexAdditionalBot?

Another variation of Yandex's supplementary crawlers, often used for specialized content discovery.

Another variation of Yandex's supplementary crawlers, often used for specialized content discovery.
YandexAdditionalBot is a production-grade search engine crawler operated by Yandex. It uses a distributed crawl infrastructure that respects crawl-delay directives, follows RFC 9309 (robots.txt) spec, and processes Sitemaps to prioritise fresh content. The user-agent string YandexAdditionalBot must be whitelisted if your site uses rate-limiting or WAF rules. Blocking impact is Critical - Blocking removes you from search results.

What happens if you block YandexAdditionalBot?

⛔ Critical Impact - Blocking YandexAdditionalBot will stop Yandex from crawling and indexing your pages. Within days or weeks you may see pages drop out of Yandex's search index entirely, resulting in a significant loss of organic search traffic. This is the most severe possible SEO consequence. Only do this intentionally, for example if you are migrating to a different search engine or decommissioning a domain. If you accidentally blocked YandexAdditionalBot, remove the rule immediately and request re-indexing via Yandex's webmaster tools.
Never block - it will remove your site from major search results.

How to block YandexAdditionalBot with robots.txt

<code>User-agent: YandexAdditionalBot</code> - Matching is case-insensitive. Robots.txt is fetched from the root of each subdomain separately.

Block completely (robots.txt)
User-agent: YandexAdditionalBot Disallow: /
Allow all (robots.txt)
User-agent: YandexAdditionalBot Allow: /
Block private only (robots.txt)
User-agent: YandexAdditionalBot Disallow: /private/ Disallow: /api/ Disallow: /admin/ Allow: /
Nginx server block
# Nginx: Hard-block YandexAdditionalBot if ($http_user_agent ~* "YandexAdditionalBot") { return 403 "Bot blocked"; }
Apache .htaccess
# Apache: Hard-block YandexAdditionalBot SetEnvIfNoCase User-Agent "YandexAdditionalBot" bad_bot Order Allow,Deny Allow from all Deny from env=bad_bot
Meta robots tag
<meta name="robots" content="noindex, nofollow">
X-Robots-Tag header
X-Robots-Tag: noindex, nofollow

Is YandexAdditionalBot safe to allow?

Yes, YandexAdditionalBot is a safe and legitimate crawler. It is operated by Yandex, which publicly documents its crawler at an official URL and follows the Robots Exclusion Protocol (RFC 9309). The user-agent string YandexAdditionalBot is verifiable via reverse-DNS lookup on the crawling IP addresses. You can safely allow it unless you have a specific reason to block (e.g., AI training opt-out or SEO tool visibility).
Verify by reverse-DNS lookup: legitimate YandexAdditionalBot requests resolve to yandex's domain.

What does YandexAdditionalBot do?

Understanding YandexAdditionalBot's purpose helps you decide whether to allow or block it.

  • Crawls and indexes web pages for search results
  • Discovers new and updated content on your website
  • Analyzes page structure, content, and links for ranking
  • Renders JavaScript to understand dynamic content
  • Checks for mobile-friendliness and page speed

Frequently Asked Questions

What is the official user-agent string for YandexAdditionalBot?
The official user-agent string for YandexAdditionalBot is: YandexAdditionalBot. This is the exact string you must use in robots.txt, Nginx, Apache, or Cloudflare firewall rules to target this bot. User-agent matching in robots.txt is case-insensitive, but the string must be spelled correctly. You can verify that a request genuinely comes from YandexAdditionalBot by performing a reverse-DNS lookup on the source IP - legitimate bots resolve back to their operator's domain.
Is YandexAdditionalBot safe?
Yes, YandexAdditionalBot is a safe and legitimate crawler. It is operated by Yandex, which publicly documents its crawler at an official URL and follows the Robots Exclusion Protocol (RFC 9309). The user-agent string YandexAdditionalBot is verifiable via reverse-DNS lookup on the crawling IP addresses. You can safely allow it unless you have a specific reason to block (e.g., AI training opt-out or SEO tool visibility).
Will blocking YandexAdditionalBot hurt my SEO?
⛔ Critical Impact - Blocking YandexAdditionalBot will stop Yandex from crawling and indexing your pages. Within days or weeks you may see pages drop out of Yandex's search index entirely, resulting in a significant loss of organic search traffic. This is the most severe possible SEO consequence. Only do this intentionally, for example if you are migrating to a different search engine or decommissioning a domain. If you accidentally blocked YandexAdditionalBot, remove the rule immediately and request re-indexing via Yandex's webmaster tools.
How do I block YandexAdditionalBot in robots.txt?
Add the following lines to your /robots.txt file:
User-agent: YandexAdditionalBot
Disallow: /

This instructs YandexAdditionalBot not to crawl any path on your site. The Disallow: / directive covers the entire domain including subfolders. To only block specific sections, replace / with the path (e.g., Disallow: /blog/). Note: robots.txt is publicly readable - any bot or human can inspect it at yourdomain.com/robots.txt.
Does YandexAdditionalBot respect robots.txt?
Yes - YandexAdditionalBot is a well-behaved bot operated by Yandex. It fetches and parses /robots.txt before crawling any page, following RFC 9309.
How do I verify if YandexAdditionalBot is crawling my site?
Search your web server access logs for the string YandexAdditionalBot (case-insensitive grep: grep -i "YandexAdditionalBot" /var/log/nginx/access.log). You can also check Google Search Console → Coverage → Crawl Stats for Googlebot variants. For YandexAdditionalBot specifically, filter by user-agent in your log analysis tool (GoAccess, AWStats, etc.).
What is the crawl frequency of YandexAdditionalBot?
Critical-impact search crawlers like YandexAdditionalBot typically crawl popular pages daily and less popular pages weekly. You can manage crawl rate via the crawl-delay directive or via the search console.
Can I block YandexAdditionalBot from specific pages only?
Yes. Instead of a global Disallow: / you can restrict YandexAdditionalBot to specific paths:
User-agent: YandexAdditionalBot
Disallow: /private/
Disallow: /staging/
Allow: /

This allows YandexAdditionalBot everywhere except the listed paths. Path matching in robots.txt uses prefix matching - Disallow: /private/ blocks /private/page.html but NOT /public/private/.
How do I check if YandexAdditionalBot is blocked by my robots.txt?
Use Google's robots.txt Tester in Search Console, or a third-party checker to simulate a YandexAdditionalBot request. You can also manually check by opening https://aicrawlercheck.com/robots.txt and scanning for YandexAdditionalBot entries. If a block exists, immediately test it against your most important URLs using the Google Search Console URL Inspection tool.
My site is blocked by YandexAdditionalBot in Search Console - what do I do?
1. Open yourdomain.com/robots.txt and look for any User-agent: YandexAdditionalBot or User-agent: * Disallow rules covering your key pages.
2. Remove or restrict the blocking rules.
3. Validate via Google Search Console → robots.txt Tester.
4. Request re-indexing using the URL Inspection tool.
5. Wait 1-2 weeks for re-crawl. Monitor Coverage report for recovery.

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