Viber user agent
Operated by Rakuten Viber
Viber is the user agent the Viber app uses to build link previews in chats.
The Viber bot at a glance
- Viber is operated by Rakuten Viber and reads page titles, descriptions and images to build link previews.
- The robots.txt token for Viber is Viber.
- Blocking a social preview bot has no effect on search rankings.
- Viber robots.txt support: Not documented.
- Recommendation for Generative Engine Optimization (GEO): Allow.
What is Viber?
Viber fetches a shared page’s title and image to show a preview in the conversation.
Rakuten Viber has not published a crawler page for this user agent.
Should you block Viber?
Allow Viber unless it causes a measurable load problem.
| Effect on search rankings | Blocking a social preview bot has no effect on search rankings. |
|---|---|
| Effect on AI visibility | No direct effect on AI answers, but shared links lose their title, image and description, which usually lowers clicks from social and chat apps. |
| Follows robots.txt | Not documented |
| Recommendation | Allow |
How to block or allow Viber
Put the robots.txt rule in the file at the root of every domain and subdomain, for example https://example.com/robots.txt. The token Viber is matched case-insensitively. robots.txt alone may not stop Viber, so add the Nginx, Apache or Cloudflare rule as well.
robots.txt: block
# Block Viber
User-agent: Viber
Disallow: /robots.txt: allow
# Allow Viber
User-agent: Viber
Allow: /robots.txt: partial
# Keep Viber out of private areas only
User-agent: Viber
Disallow: /wp-admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Allow: /Nginx
# Nginx: return 403 to Viber
if ($http_user_agent ~* "(Viber)") {
return 403;
}Apache
# Apache .htaccess: return 403 to Viber
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (Viber) [NC]
RewriteRule .* - [F,L]Cloudflare WAF
# Cloudflare > Security > WAF > Custom rule, action: Block
(http.user_agent contains "Viber")How to verify real Viber traffic
Rakuten Viber publishes no IP list or reverse DNS pattern for Viber, so the user agent cannot be verified. Anyone can send the same string. Rate-limit unusual volume instead of trusting the name.
How to find Viber in your server logs
Search the web server access log for the token. The command below counts Viber requests per URL on Nginx or Apache.
grep -i "Viber" access.log | awk '{print $7}' | sort | uniq -c | sort -rn | head -20For a full report per AI bot, upload the log to the AI Log File Analyzer, a free tool by Justin Hà.
Viber user agent string
The full user agent Rakuten Viber publishes for Viber. Version numbers such as Chrome/W.X.Y.Z change over time, so match the token, not the whole string.
ViberViber FAQ
Viber identifies itself with the robots.txt token "Viber". A typical request header reads: Viber
Rakuten Viber has not documented how Viber treats robots.txt. Add a robots.txt rule and back it with a server rule if the traffic matters to you.
Blocking a social preview bot has no effect on search rankings. No direct effect on AI answers, but shared links lose their title, image and description, which usually lowers clicks from social and chat apps.
Add two lines to the robots.txt file at the root of each domain and subdomain: "User-agent: Viber" followed by "Disallow: /". The token is case-insensitive. Changes can take up to 24 hours to be picked up.
Not reliably. Rakuten Viber publishes no IP list or reverse DNS pattern for Viber, so anyone can send the same user agent. Rate-limit unusual volume instead of trusting the name.
Search your server access log for "Viber", for example with: grep -i "Viber" access.log. The AI Log File Analyzer by Justin Hà counts visits per AI bot from an uploaded log file.
Sources: Public bot registry. Last reviewed by Justin Hà.
See which of these bots actually reach your website
The AI Log File Analyzer by Justin Hà counts visits from GPTBot, ClaudeBot, PerplexityBot and other AI crawlers in your server log, for free. The GEO Technical Package sets up robots.txt, llms.txt and crawler access for AI search.
