Viber
Rakuten Viber •
Since 2013
Quick Actions
Official Docs
What is Viber?
ViberBot generates link previews when users share URLs in Viber messages. Viber is a popular messaging app with over 1 billion users globally, particularly strong in Eastern Europe, Middle East, and parts of Asia. The bot fetches page metadata and images to create rich previews that appear in chats, helping users understand linked content before clicking. For businesses using Viber for customer communication or marketing, proper preview rendering is important for engagement.
User Agent String
Mozilla/5.0 (compatible; ViberBot/1.0; +https://developers.viber.com)
How to Control Viber
Block Completely
To prevent Viber from accessing your entire website, add this to your robots.txt file:
# Block Viber
User-agent: ViberBot
Disallow: /
Block Specific Directories
To restrict access to certain parts of your site while allowing others:
User-agent: ViberBot
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: ViberBot
Crawl-delay: 10
How to Verify Viber
Verification Method:
Viber bot identification
Viber bot identification
Learn more in the official documentation.
Detection Patterns
Multiple ways to detect Viber in your application:
Basic Pattern
/Viber/i
Strict Pattern
/^Mozilla/5\.0 \(compatible; ViberBot/1\.0; \+https\://developers\.viber\.com\)$/
Flexible Pattern
/Viber[\s\/]?[\d\.]*?/i
Vendor Match
/.*Rakuten Viber.*Viber/i
Implementation Examples
// PHP Detection for Viber
function detect_viber() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/Viber/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('Viber 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($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
# Python/Flask Detection for Viber
import re
from flask import request, make_response
def detect_viber():
user_agent = request.headers.get('User-Agent', '')
pattern = r'Viber'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False
# Django Middleware
class ViberMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
// JavaScript/Node.js Detection for Viber
const express = require('express');
const app = express();
// Middleware to detect Viber
function detectViber(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /Viber/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('Viber detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'Viber';
}
next();
}
app.use(detectViber);
# Apache .htaccess rules for Viber
# Block completely
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} Viber [NC]
RewriteRule .* - [F,L]
# Or redirect to a static version
RewriteCond %{HTTP_USER_AGENT} Viber [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]
# Or set environment variable for PHP
SetEnvIfNoCase User-Agent "Viber" is_bot=1
# Add cache headers for this bot
<If "%{HTTP_USER_AGENT} =~ /Viber/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
# Nginx configuration for Viber
# Map user agent to variable
map $http_user_agent $is_viber {
default 0;
~*Viber 1;
}
server {
# Block the bot completely
if ($is_viber) {
return 403;
}
# Or serve cached content
location / {
if ($is_viber) {
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_viber) {
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
User-agent: ViberBot
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
User-agent: ViberBot
Crawl-delay: 10
Disallow: /wp-admin/
Disallow: /drafts/
Disallow: /preview/
Disallow: /*?replytocom=
Allow: /
SaaS/Application Configuration
User-agent: ViberBot
Disallow: /app/
Disallow: /api/
Disallow: /dashboard/
Disallow: /settings/
Allow: /
Allow: /pricing/
Allow: /features/
Allow: /docs/
Quick Reference
User Agent Match
Viber
Robots.txt Name
ViberBot
Category
social
Respects robots.txt
Yes
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