What is Grammarly?
GrammarlyBot is used by Grammarly's writing assistant platform to analyze web content and provide writing suggestions. As Grammarly has expanded from a simple grammar checker to a comprehensive AI-powered writing assistant, their bot helps understand various writing contexts and styles across the web. This enables Grammarly to provide more accurate and contextual suggestions to its users. The bot may access public content to improve Grammarly's understanding of language patterns and writing styles across different domains and industries.
User Agent String
Mozilla/5.0 (compatible; GrammarlyBot/1.0; +https://www.grammarly.com/bot)
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How to Control Grammarly
Block Completely
To prevent Grammarly from accessing your entire website, add this to your robots.txt file:
User-agent: GrammarlyBot
Disallow: /
Block Specific Directories
To restrict access to certain parts of your site while allowing others:
User-agent: GrammarlyBot
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: GrammarlyBot
Crawl-delay: 10
How to Verify Grammarly
Verification Method:
Verify Grammarly user agent
Learn more in the official documentation .
Detection Patterns
Multiple ways to detect Grammarly in your application:
Basic Pattern
/Grammarly/i
Strict Pattern
/^Mozilla/5\.0 \(compatible; GrammarlyBot/1\.0; \+https\://www\.grammarly\.com/bot\)$/
Flexible Pattern
/Grammarly[\s\/]?[\d\.]*?/i
Vendor Match
/.*Grammarly.*Grammarly/i
Implementation Examples
PHP
Python
JavaScript
.htaccess
Nginx
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function detect_grammarly() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/Grammarly/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('Grammarly 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($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
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import re
from flask import request, make_response
def detect_grammarly():
user_agent = request.headers.get('User-Agent', '')
pattern = r'Grammarly'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False
class GrammarlyMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
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const express = require('express');
const app = express();
// Middleware to detect Grammarly
function detectGrammarly(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /Grammarly/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('Grammarly detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'Grammarly';
}
next();
}
app.use(detectGrammarly);
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RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} Grammarly [NC]
RewriteRule .* - [F,L]
RewriteCond %{HTTP_USER_AGENT} Grammarly [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]
SetEnvIfNoCase User-Agent "Grammarly" is_bot=1
<If "%{HTTP_USER_AGENT} =~ /Grammarly/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
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map $http_user_agent $is_grammarly {
default 0;
~*Grammarly 1;
}
server {
if ($is_grammarly) {
return 403;
}
location / {
if ($is_grammarly) {
root /var/www/cached;
try_files $uri $uri.html $uri/index.html @backend;
}
try_files $uri @backend;
}
location @backend {
if ($is_grammarly) {
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: GrammarlyBot
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: GrammarlyBot
Crawl-delay: 10
Disallow: /wp-admin/
Disallow: /drafts/
Disallow: /preview/
Disallow: /*?replytocom=
Allow: /
SaaS/Application Configuration
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User-agent: GrammarlyBot
Disallow: /app/
Disallow: /api/
Disallow: /dashboard/
Disallow: /settings/
Allow: /
Allow: /pricing/
Allow: /features/
Allow: /docs/
Quick Reference
User Agent Match
Grammarly
Robots.txt Name
GrammarlyBot
Category
other
Respects robots.txt
Yes