SemrushBot-SI user agent
Operated by Semrush
SemrushBot-SI is the Semrush crawler for the On Page SEO Checker and similar tools.
The SemrushBot-SI bot at a glance
- SemrushBot-SI is operated by Semrush and fetches pages to power a specific product feature.
- The robots.txt token for SemrushBot-SI is SemrushBot-SI.
- Blocking an SEO tool crawler has no effect on Google or Bing rankings.
- SemrushBot-SI robots.txt support: Yes.
- Recommendation for Generative Engine Optimization (GEO): Your choice.
What is SemrushBot-SI?
SemrushBot-SI reads pages a Semrush user is optimizing to suggest on-page improvements.
Semrush documents it as a separate robots.txt token.
Should you block SemrushBot-SI?
Blocking SemrushBot-SI is a business decision: it protects your content but can lower how well AI products know your brand.
| Effect on search rankings | Blocking an SEO tool crawler has no effect on Google or Bing rankings. |
|---|---|
| Effect on AI visibility | No effect on AI answers. Blocking hides your pages and backlinks from that SEO tool, including from competitors who use it, and breaks your own audits in that tool. |
| Follows robots.txt | Yes |
| Recommendation | Your choice |
How to block or allow SemrushBot-SI
Put the robots.txt rule in the file at the root of every domain and subdomain, for example https://example.com/robots.txt. The token SemrushBot-SI is matched case-insensitively.
robots.txt: block
# Block SemrushBot-SI
User-agent: SemrushBot-SI
Disallow: /robots.txt: allow
# Allow SemrushBot-SI
User-agent: SemrushBot-SI
Allow: /robots.txt: partial
# Keep SemrushBot-SI out of private areas only
User-agent: SemrushBot-SI
Disallow: /wp-admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Allow: /Nginx
# Nginx: return 403 to SemrushBot-SI
if ($http_user_agent ~* "(SemrushBot\-SI)") {
return 403;
}Apache
# Apache .htaccess: return 403 to SemrushBot-SI
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (SemrushBot\-SI) [NC]
RewriteRule .* - [F,L]Cloudflare WAF
# Cloudflare > Security > WAF > Custom rule, action: Block
(http.user_agent contains "SemrushBot-SI")How to verify real SemrushBot-SI traffic
Semrush publishes no IP list or reverse DNS pattern for SemrushBot-SI, so the user agent cannot be verified. Anyone can send the same string. Rate-limit unusual volume instead of trusting the name.
How to find SemrushBot-SI in your server logs
Search the web server access log for the token. The command below counts SemrushBot-SI requests per URL on Nginx or Apache.
grep -i "SemrushBot-SI" access.log | awk '{print $7}' | sort | uniq -c | sort -rn | head -20For a full report per AI bot, upload the log to the AI Log File Analyzer, a free tool by Justin Hà.
SemrushBot-SI FAQ
SemrushBot-SI uses the robots.txt token "SemrushBot-SI". Semrush does not publish a full user-agent string, so match the token inside the User-Agent header.
Yes. Semrush states that SemrushBot-SI follows robots.txt rules written for the "SemrushBot-SI" token.
Blocking an SEO tool crawler has no effect on Google or Bing rankings. No effect on AI answers. Blocking hides your pages and backlinks from that SEO tool, including from competitors who use it, and breaks your own audits in that tool.
Add two lines to the robots.txt file at the root of each domain and subdomain: "User-agent: SemrushBot-SI" followed by "Disallow: /". The token is case-insensitive. Changes can take up to 24 hours to be picked up.
Not reliably. Semrush publishes no IP list or reverse DNS pattern for SemrushBot-SI, so anyone can send the same user agent. Rate-limit unusual volume instead of trusting the name.
Search your server access log for "SemrushBot-SI", for example with: grep -i "SemrushBot-SI" access.log. The AI Log File Analyzer by Justin Hà counts visits per AI bot from an uploaded log file.
Sources: Semrush crawler documentation. Last reviewed by Justin Hà.
See which of these bots actually reach your website
The AI Log File Analyzer by Justin Hà counts visits from GPTBot, ClaudeBot, PerplexityBot and other AI crawlers in your server log, for free. The GEO Technical Package sets up robots.txt, llms.txt and crawler access for AI search.
