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

SemrushBot

SemrushBot is the main web crawler for Semrush, a leading digital marketing and competitive intelligence platform. Its purpose is to scan websites to collect the data that powers Semrush's suite of SEO, content marketing, and competitive analysis tools. While its crawling provides great value to Semrush customers, some website owners may have concerns about the server load or the gathering of competitive intelligence on their site.

What is SemrushBot?

SemrushBot is the web crawler for Semrush, a provider of digital marketing and SEO tools. The bot serves as the data collection engine for Semrush's services, systematically visiting websites to gather information about their structure, content, and backlink profiles. The bot identifies itself with user-agent strings like Mozilla/5.0 (compatible; SemrushBot/7~bl; +http://www.semrush.com/bot.html). It is designed to respect standard web protocols and to crawl in a way that minimizes server load.

Why is SemrushBot crawling my site?

SemrushBot is visiting your website to collect data for its competitive analysis and SEO tools. It gathers information about your site's structure, content, keywords, and backlink profile. The frequency of its visits is determined by factors like your site's popularity and how often its content changes. Prominent sites in industries where Semrush has many customers may be crawled more frequently. The bot's activity is a standard industry practice for gathering competitive intelligence.

What is the purpose of SemrushBot?

The purpose of SemrushBot is to collect the data that powers the Semrush suite of digital marketing tools. The information allows Semrush users to analyze competitors' SEO strategies, track keyword rankings, and audit websites for technical SEO issues. For website owners, the bot's activity can be indirectly valuable, as the data contributes to tools that many marketers use to improve their websites. If you are a Semrush customer, the bot's crawling ensures you have access to accurate, up-to-date information.

How do I block SemrushBot?

To prevent SemrushBot from collecting data from your website, you can add a disallow rule to your robots.txt file. This is the standard method for managing access for legitimate SEO crawlers.

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

User-agent: SemrushBot
Disallow: /

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

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., Semrush), 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.