444 No Response

HTTP response status code 444 No Response is an unofficial client error specific to nginx. The server closes the HTTP Connection without sending any data back to the client, including this HTTP status code itself.

Usage

The 444 No Response status code instructs nginx to close the connection immediately and send nothing to the client. This code appears only in the nginx logs and is never transmitted over the wire. Blocking malicious HTTP requests is the primary use case, such as requests with illegal Host headers or suspicious patterns.

A typical nginx configuration returns 444 inside a location block or server block to silently drop unwanted traffic.

SEO impact

Search engines like Google do not index a URL with 444 No Response response status. URLs previously indexed with this code are removed from search results.

Example

A client sends a request with a suspicious Host header. The nginx server is configured to drop the connection for unrecognized hosts. The 444 status code appears in the nginx access log but no response reaches the client.

Request

GET / HTTP/1.1
Host: malicious.example.re

Response (nginx log entry only)

192.168.1.50 - - [02/Mar/2026:10:15:30 +0000] "GET / HTTP/1.1" 444 0 "-" "curl/8.1.2"

No HTTP response is sent. The connection closes immediately.

How to fix

Search the nginx configuration files for all return 444 directives. These intentional connection drops target specific request patterns:

if ($host !~* ^(example\.re)$) {
    return 444;
}

Run grep -rn 'return 444' /etc/nginx/ to locate every rule producing this response. Common locations include the default server block (catching requests for unknown Host headers), location blocks with pattern-based deny rules, and if conditions matching suspicious User-Agent strings.

Review the nginx access log for the request URI, IP, and User-Agent associated with the 444. Cross-reference this data with the configuration rules to confirm whether the block is intentional or a false positive.

Check deny and allow directives in the server or location block. A blanket deny all combined with a limited allow list silently drops legitimate traffic when the client IP changes or falls outside the allowed range:

allow 192.168.1.0/24;
deny all;
return 444;

Verify the Host header in the client request matches an active server_name directive. Requests arriving at the default server block (the catch-all for unrecognized hosts) are the most common trigger for 444 responses.

Enable the nginx error log at info level to surface additional detail about why a connection was dropped:

error_log /var/log/nginx/error.log info;

This status code is always an intentional server decision. The fix depends on whether the block rule is correct or misconfigured.

Takeaway

The 444 No Response status code is a nginx client error never sent to the client. The HTTP Connection closes silently and the event is recorded only in the nginx logs.

See also

Last updated: March 6, 2026