s4a/seo4ajax.com
JavaScript rendering and SEO prerendering service
About this crawler
s4a/seo4ajax.com is a web crawler identified by the regular-expression pattern s4a\/|seo4ajax\.com in the User-Agent request header. It is categorised as seo. Use the regex above to detect, log, allow, or block s4a/seo4ajax.com traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
0.33%
Technical details
- Name
- s4a/seo4ajax.com
- Pattern
s4a\/|seo4ajax\.com- Tags
- seo
- Reference
- https://www.seo4ajax.com/
- Added
- 2026/04/17
- Instances
- 2 known sample(s)
Sample User-Agent strings
Mozilla/5.0 AppleWebKit (compatible; s4a/1.0; +https://www.seo4ajax.com/webscraper)
seo4ajax.com
Block this crawler
robots.txt — disallow s4a/seo4ajax.com:
User-agent: s4a/seo4ajax.com
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} s4a\/|seo4ajax\.com [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "s4a\\/|seo4ajax\\.com") {
return 403;
}
← back to all crawlers