Published on 2025-08-07T06:18:08Z

YandexRCA bot

YandexRCA is a web crawler from the Russian search engine Yandex. While its specific function is not publicly detailed by Yandex, it is part of the broader crawling infrastructure that collects web content to improve its search engine and related services. Its presence on your site is a standard part of Yandex's indexing operations.

What is YandexRCA?

YandexRCA is a web crawler from the Russian technology company Yandex. It is a specialized bot within Yandex's crawling infrastructure, designed to collect and analyze web content. The bot identifies itself in server logs with the user-agent string Mozilla/5.0 (compatible; YandexRCA/1.0; +http://yandex.com/bots). The 'RCA' in its name likely refers to a specific internal function, but Yandex has not specified what it stands for. The bot operates from Yandex's IP infrastructure, primarily from Russian servers.

Why is YandexRCA crawling my site?

YandexRCA is visiting your website to collect information that helps Yandex improve its search engine and other services. If you are seeing this bot, it means your site contains content that Yandex considers valuable. The frequency of visits depends on factors like your site's popularity and content update schedule. The bot's visits are a standard and authorized web crawling activity.

What is the purpose of YandexRCA?

The purpose of YandexRCA is to support the Yandex search engine by gathering and analyzing web content. While its exact function is not documented, it likely contributes to Yandex's ability to deliver relevant search results. For website owners, having your content properly indexed by Yandex can provide value by making your site discoverable to Yandex users, particularly those in Russia and other countries where Yandex has a substantial market share.

How do I block YandexRCA?

To prevent YandexRCA from accessing your website, you can add a specific disallow rule to your robots.txt file. This is the standard method for managing crawler access.

To block this bot, add the following lines to your robots.txt file:

User-agent: YandexRCA
Disallow: /

How to verify the authenticity of the user-agent operated by Yandex?

Reverse IP lookup technique

To verify user-agent authenticity, you can use host linux command two times with the IP address of the requester.
  1. > host IPAddressOfRequest
    This command returns the reverse lookup hostname (e.g., 4.4.8.8.in-addr.arpa.). 
  2. > host ReverseDNSFromTheOutputOfFirstRequest
If the output matches the original IP address and the domain is associated with a trusted operator (e.g., Yandex), the user-agent can be considered legitimate.

IP list lookup technique

Some operators provide a public list of IP addresses used by their crawlers. This list can be cross-referenced to verify a user-agent's authenticity. However, both operators and website owners may find it challenging to maintain an up-to-date list, so use this method with caution and in conjunction with other verification techniques.