01 · Operator
Who operates CheckHost
- Company
- Check-Host.net
- Type
- Monitoring bot
- Official docs
- check-host.net
02 · Behavior
What CheckHost does
Check-Host.net runs ping, HTTP, TCP, UDP and DNS checks from check nodes worldwide. A request appears when someone tests your site on check-host.net. The service publishes its list of check nodes.
03 · Impact
Why CheckHost matters for your site
If you allow it
- Lets you and others test availability from many countries
- Low, on-demand traffic
If you block it
- Anyone can trigger checks against your site
04 · Allow
How to allow CheckHost
robots.txt
User-agent: CheckHost
Allow: /Cloudflare
# Security › WAF › Custom rules › Create rule
Expression: (http.user_agent contains "CheckHost")
Action: Skip › All Super Bot Fight Mode rules
# Also check Security › Bots: "Block AI bots" can block it regardless of robots.txt.WordPress
# WordPress serves a virtual robots.txt. Edit it with your SEO plugin:
# Yoast: SEO › Tools › File editor · Rank Math: General Settings › Edit robots.txt
User-agent: CheckHost
Allow: /nginx
# nginx serves every user agent by default.
# Make sure no rule like this blocks it:
# if ($http_user_agent ~* "CheckHost") { return 403; }Apache
# Apache serves every user agent by default.
# Make sure .htaccess has no rule like this:
# RewriteCond %{HTTP_USER_AGENT} CheckHost [NC]
# RewriteRule .* - [F,L]05 · Block
How to block CheckHost
Start with robots.txt. If CheckHost keeps showing up in your logs, block it at your CDN or web server.
robots.txt
User-agent: CheckHost
Disallow: /Cloudflare
# Security › WAF › Custom rules › Create rule
Expression: (http.user_agent contains "CheckHost")
Action: BlockWordPress
# WordPress serves a virtual robots.txt. Edit it with your SEO plugin:
# Yoast: SEO › Tools › File editor · Rank Math: General Settings › Edit robots.txt
User-agent: CheckHost
Disallow: /nginx
# In your server { } block:
if ($http_user_agent ~* "CheckHost") {
return 403;
}Apache
# .htaccess
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} CheckHost [NC]
RewriteRule .* - [F,L]
</IfModule>06 · User agents
User agents we see for CheckHost
The user agent published by the operator:
CheckHost (https://check-host.net/)07 · Verification
Is it really CheckHost?
Anyone can copy a user agent. Real CheckHost requests come from the IP ranges published at check-host.net/nodes/ips.
FAQ
Questions about CheckHost
Why is CheckHost visiting my site?
Someone used check-host.net to test whether your site is reachable from different locations.
How can I verify CheckHost requests?
Compare the source IP with the node list Check-Host.net publishes at check-host.net/nodes/ips.
How do I block CheckHost?
Block the user agent or the published node IPs at your server or firewall.
Last reviewed Oct 7, 2026