What is SemrushBot-SA?
SemrushBot-SA is Semrush's specialized crawler for their Site Audit tool. Unlike the general SemrushBot, this crawler only operates when website owners or authorized users initiate site audits within Semrush. It performs deep technical SEO analysis, checking for issues like broken links, duplicate content, crawlability problems, and site structure issues. The bot provides detailed technical reports that help SEO professionals optimize their websites. It only crawls sites explicitly added to Semrush projects.
User Agent String
Mozilla/5.0 (compatible; SemrushBot-SA/0.97; +http://www.semrush.com/bot.html)
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How to Control SemrushBot-SA
Block Completely
To prevent SemrushBot-SA from accessing your entire website, add this to your robots.txt file:
User-agent: SemrushBot-SA
Disallow: /
Block Specific Directories
To restrict access to certain parts of your site while allowing others:
User-agent: SemrushBot-SA
Disallow: /admin/
Disallow: /private/
Disallow: /wp-admin/
Allow: /public/
Set Crawl Delay
To slow down the crawl rate (note: not all bots respect this directive):
User-agent: SemrushBot-SA
Crawl-delay: 10
How to Verify SemrushBot-SA
Verification Method:
Originates from Semrush infrastructure
Learn more in the official documentation .
Detection Patterns
Multiple ways to detect SemrushBot-SA in your application:
Basic Pattern
/SemrushBot\-SA/i
Strict Pattern
/^Mozilla/5\.0 \(compatible; SemrushBot\-SA/0\.97; \+http\://www\.semrush\.com/bot\.html\)$/
Flexible Pattern
/SemrushBot\-SA[\s\/]?[\d\.]*?/i
Vendor Match
/.*Semrush.*SemrushBot\-SA/i
Implementation Examples
PHP
Python
JavaScript
.htaccess
Nginx
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function detect_semrushbot_sa() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/SemrushBot\\-SA/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('SemrushBot-SA detected from IP: ' . $_SERVER['REMOTE_ADDR']);
// Set cache headers
header('Cache-Control: public, max-age=3600');
header('X-Robots-Tag: noarchive');
// Optional: Serve cached version
if (file_exists('cache/' . md5($_SERVER['REQUEST_URI']) . '.html')) {
readfile('cache/' . md5($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
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import re
from flask import request, make_response
def detect_semrushbot_sa():
user_agent = request.headers.get('User-Agent', '')
pattern = r'SemrushBot-SA'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False
class SemrushBotSAMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
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const express = require('express');
const app = express();
// Middleware to detect SemrushBot-SA
function detectSemrushBotSA(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /SemrushBot-SA/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('SemrushBot-SA detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'SemrushBot-SA';
}
next();
}
app.use(detectSemrushBotSA);
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RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} SemrushBot\-SA [NC]
RewriteRule .* - [F,L]
RewriteCond %{HTTP_USER_AGENT} SemrushBot\-SA [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]
SetEnvIfNoCase User-Agent "SemrushBot\-SA" is_bot=1
<If "%{HTTP_USER_AGENT} =~ /SemrushBot\-SA/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
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map $http_user_agent $is_semrushbot_sa {
default 0;
~*SemrushBot\-SA 1;
}
server {
if ($is_semrushbot_sa) {
return 403;
}
location / {
if ($is_semrushbot_sa) {
root /var/www/cached;
try_files $uri $uri.html $uri/index.html @backend;
}
try_files $uri @backend;
}
location @backend {
if ($is_semrushbot_sa) {
add_header Cache-Control "public, max-age=3600";
add_header X-Robots-Tag "noarchive";
}
proxy_pass http://backend;
}
}
Should You Block This Bot?
Recommendations based on your website type:
Site Type
Recommendation
Reasoning
E-commerce
Optional
Evaluate based on bandwidth usage vs. benefits
Blog/News
Allow
Increases content reach and discoverability
SaaS Application
Block
No benefit for application interfaces; preserve resources
Documentation
Selective
Allow for public docs, block for internal docs
Corporate Site
Limit
Allow for public pages, block sensitive areas like intranets
Advanced robots.txt Configurations
E-commerce Site Configuration
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User-agent: SemrushBot-SA
Crawl-delay: 5
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Disallow: /api/
Disallow: /*?sort=
Disallow: /*?filter=
Disallow: /*&page=
Allow: /products/
Allow: /categories/
Sitemap: https://example.com/sitemap.xml
Publishing/Blog Configuration
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User-agent: SemrushBot-SA
Crawl-delay: 10
Disallow: /wp-admin/
Disallow: /drafts/
Disallow: /preview/
Disallow: /*?replytocom=
Allow: /
SaaS/Application Configuration
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User-agent: SemrushBot-SA
Disallow: /app/
Disallow: /api/
Disallow: /dashboard/
Disallow: /settings/
Allow: /
Allow: /pricing/
Allow: /features/
Allow: /docs/
Quick Reference
User Agent Match
SemrushBot-SA
Robots.txt Name
SemrushBot-SA
Category
seo
Respects robots.txt
Yes