Selenium
Selenium browser automation web crawler
About this crawler
Selenium is a web crawler identified by the regular-expression pattern Selenium in the User-Agent request header. It is categorised as browser-automation. Use the regex above to detect, log, allow, or block Selenium traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
No block-rate data for this crawler.
Technical details
- Name
- Selenium
- Pattern
Selenium- Tags
- browser-automation
- Reference
- https://www.selenium.dev
- Added
- 2026/04/07
- rDNS suffixes
.selenium.dev- Instances
- 1 known sample(s)
rDNS verification (FCrDNS)
Verify a request is genuinely Selenium with forward-confirmed reverse DNS: the client IP's PTR record must end in one of the suffixes below and a forward A/AAAA lookup of that hostname must return the same IP. UA strings alone are spoofable; FCrDNS is not.
.selenium.dev
Sample User-Agent strings
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36; Selenium
Block this crawler
robots.txt — disallow Selenium:
User-agent: Selenium
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} Selenium [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "Selenium") {
return 403;
}
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