BingPreview is Microsoft's specialized crawler that generates page snapshots and previews shown in Bing search results. This bot captures visual representations of web pages, creating the thumbnail images and preview snippets that help users decide which results to click. BingPreview works alongside regular Bingbot but focuses specifically on visual capture rather than content indexing. The crawler uses modern rendering technology to accurately capture how pages appear to users, including JavaScript-rendered content. These previews enhance the search experience by giving users a visual preview before they visit a site.
User Agent String
Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534+ (KHTML, like Gecko) BingPreview/1.0b
How to Control BingPreview
Block Completely
To prevent BingPreview from accessing your entire website, add this to your robots.txt file:
Multiple ways to detect BingPreview in your application:
Basic Pattern
/BingPreview/i
Strict Pattern
/^Mozilla/5\.0 \(Windows NT 6\.1; WOW64\) AppleWebKit/534\+ \(KHTML, like Gecko\) BingPreview/1\.0b$/
Flexible Pattern
/BingPreview[\s\/]?[\d\.]*?/i
Vendor Match
/.*Microsoft.*BingPreview/i
Implementation Examples
// PHP Detection for BingPreview
function detect_bingpreview() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/BingPreview/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('BingPreview 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($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
# Python/Flask Detection for BingPreview
import re
from flask import request, make_responsedef detect_bingpreview():
user_agent = request.headers.get('User-Agent', '')
pattern = r'BingPreview'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False# Django Middleware
class BingPreviewMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
// JavaScript/Node.js Detection for BingPreview
const express = require('express');
const app = express();// Middleware to detect BingPreview
function detectBingPreview(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /BingPreview/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('BingPreview detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'BingPreview';
}
next();
}app.use(detectBingPreview);
# Apache .htaccess rules for BingPreview# Block completely
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} BingPreview [NC]
RewriteRule .* - [F,L]# Or redirect to a static version
RewriteCond %{HTTP_USER_AGENT} BingPreview [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]# Or set environment variable for PHP
SetEnvIfNoCase User-Agent "BingPreview" is_bot=1# Add cache headers for this bot
<If "%{HTTP_USER_AGENT} =~ /BingPreview/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
# Nginx configuration for BingPreview# Map user agent to variable
map $http_user_agent $is_bingpreview {
default 0;
~*BingPreview 1;
}server {
# Block the bot completely
if ($is_bingpreview) {
return 403;
}
# Or serve cached content
location / {
if ($is_bingpreview) {
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_bingpreview) {
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
Allow
Essential for product visibility in search results
Blog/News
Allow
Increases content reach and discoverability
SaaS Application
Block
No benefit for application interfaces; preserve resources
Documentation
Allow
Improves documentation discoverability for developers
Corporate Site
Allow
Allow for public pages, block sensitive areas like intranets