What is ICC-Crawler?
ICC-Crawler is operated by NICT (National Institute of Information and Communications Technology), a Japanese research institution. The bot collects web pages for research into advanced information processing, including multilingual natural language processing and machine translation. It respects robots.txt directives and is used strictly for academic research purposes.
User Agent String
ICC-Crawler/3.0 (Mozilla-compatible; ; https://ucri.nict.go.jp/en/icccrawler.html)
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How to Control ICC-Crawler
Block Completely
To prevent ICC-Crawler from accessing your entire website, add this to your robots.txt file:
User-agent: ICC-Crawler
Disallow: /
Block Specific Directories
To restrict access to certain parts of your site while allowing others:
User-agent: ICC-Crawler
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: ICC-Crawler
Crawl-delay: 10
How to Verify ICC-Crawler
Verification Method:
Verify requests originate from NICT IP ranges
Learn more in the official documentation .
Detection Patterns
Multiple ways to detect ICC-Crawler in your application:
Basic Pattern
/ICC\-Crawler/i
Strict Pattern
/^ICC\-Crawler/3\.0 \(Mozilla\-compatible; ; https\://ucri\.nict\.go\.jp/en/icccrawler\.html\)$/
Flexible Pattern
/ICC\-Crawler[\s\/]?[\d\.]*?/i
Vendor Match
/.*NICT.*ICC\-Crawler/i
Implementation Examples
PHP
Python
JavaScript
.htaccess
Nginx
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function detect_icc_crawler() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/ICC\\-Crawler/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('ICC-Crawler 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($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
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import re
from flask import request, make_response
def detect_icc_crawler():
user_agent = request.headers.get('User-Agent', '')
pattern = r'ICC-Crawler'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False
class ICCCrawlerMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
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const express = require('express');
const app = express();
// Middleware to detect ICC-Crawler
function detectICCCrawler(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /ICC-Crawler/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('ICC-Crawler detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'ICC-Crawler';
}
next();
}
app.use(detectICCCrawler);
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RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} ICC\-Crawler [NC]
RewriteRule .* - [F,L]
RewriteCond %{HTTP_USER_AGENT} ICC\-Crawler [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]
SetEnvIfNoCase User-Agent "ICC\-Crawler" is_bot=1
<If "%{HTTP_USER_AGENT} =~ /ICC\-Crawler/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
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map $http_user_agent $is_icc_crawler {
default 0;
~*ICC\-Crawler 1;
}
server {
if ($is_icc_crawler) {
return 403;
}
location / {
if ($is_icc_crawler) {
root /var/www/cached;
try_files $uri $uri.html $uri/index.html @backend;
}
try_files $uri @backend;
}
location @backend {
if ($is_icc_crawler) {
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: ICC-Crawler
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: ICC-Crawler
Crawl-delay: 10
Disallow: /wp-admin/
Disallow: /drafts/
Disallow: /preview/
Disallow: /*?replytocom=
Allow: /
SaaS/Application Configuration
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User-agent: ICC-Crawler
Disallow: /app/
Disallow: /api/
Disallow: /dashboard/
Disallow: /settings/
Allow: /
Allow: /pricing/
Allow: /features/
Allow: /docs/
Quick Reference
User Agent Match
ICC-Crawler
Robots.txt Name
ICC-Crawler
Category
other
Respects robots.txt
Yes