CCBot is the web crawler operated by Common Crawl, a non-profit organization that builds and maintains open datasets of web crawl data. Since 2011, Common Crawl has been creating monthly snapshots of billions of web pages, making this data freely available to researchers, companies, and individuals. The datasets produced by CCBot have become fundamental resources for training large language models and other AI systems, with major tech companies and research institutions relying on Common Crawl data. The bot follows ethical crawling practices, respects robots.txt, and operates at a scale that captures a significant portion of the public web. By making web data accessible in a structured format, Common Crawl democratizes access to web-scale datasets that would otherwise be available only to large corporations.
User Agent String
CCBot/2.0 (https://commoncrawl.org/faq/)
How to Control CCBot
Block Completely
To prevent CCBot from accessing your entire website, add this to your robots.txt file:
# Block CCBot
User-agent: CCBot
Disallow: /
Block Specific Directories
To restrict access to certain parts of your site while allowing others:
⚠️ AI Training Notice
This bot may collect and use your website content for AI model training. Consider whether you want your content used for this purpose before allowing access.
Detection Patterns
Multiple ways to detect CCBot in your application:
Basic Pattern
/CCBot/i
Strict Pattern
/^CCBot/2\.0 \(https\://commoncrawl\.org/faq/\)$/
Flexible Pattern
/CCBot[\s\/]?[\d\.]*?/i
Vendor Match
/.*Common Crawl.*CCBot/i
Implementation Examples
// PHP Detection for CCBot
function detect_ccbot() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/CCBot/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('CCBot 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($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
# Python/Flask Detection for CCBot
import re
from flask import request, make_response
def detect_ccbot():
user_agent = request.headers.get('User-Agent', '')
pattern = r'CCBot'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False
# Django Middleware
class CCBotMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
// JavaScript/Node.js Detection for CCBot
const express = require('express');
const app = express();
// Middleware to detect CCBot
function detectCCBot(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /CCBot/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('CCBot detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'CCBot';
}
next();
}
app.use(detectCCBot);
# Apache .htaccess rules for CCBot# Block completely
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} CCBot [NC]
RewriteRule .* - [F,L]
# Or redirect to a static version
RewriteCond %{HTTP_USER_AGENT} CCBot [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]
# Or set environment variable for PHP
SetEnvIfNoCase User-Agent "CCBot" is_bot=1
# Add cache headers for this bot
<If "%{HTTP_USER_AGENT} =~ /CCBot/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
# Nginx configuration for CCBot# Map user agent to variable
map $http_user_agent $is_ccbot {
default 0;
~*CCBot 1;
}
server {
# Block the bot completely
if ($is_ccbot) {
return 403;
}
# Or serve cached content
location / {
if ($is_ccbot) {
root /var/www/cached;
try_files $uri $uri.html $uri/index.html @backend;
}
try_files $uri @backend;
}
# Add headers for bot requests
location @backend {
if ($is_ccbot) {
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
Limit Access
Protect pricing and inventory data from AI training
Blog/News
Consider Blocking
Your content may be used for AI training without compensation
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
