A 444 No Response error is an nginx-specific code for: "nginx deliberately hung up on your request without sending any data back.".

How do I fix or troubleshoot a 444 Error?

Common steps include reloading the page in your browser, checking for typos in the URL, verifying server status, clearing browser cache or cookies, and contacting the website owner or server administrator if the error persists.

444 Error | Error-Message.Net

A 444 No Response error is an unofficial status code internal to the nginx web server.

When an nginx configuration instructs the server to return code 444, nginx immediately terminates the TCP connection and closes the socket without returning any HTTP headers or body payload to the client.

Determining why

System administrators configure nginx to return 444 as a defense mechanism against malicious traffic:

To silently drop automated bots, vulnerability scanners, and DDoS floods without wasting server bandwidth.
When a request arrives with an unrecognized or missing Host header.
When requests target disallowed URL patterns (like /wp-admin or /.env on a non-WordPress server).

Steps you could possibly take:

Check the website address - Ensure you typed the domain name correctly and are not attempting to access the server via its raw numerical IP address.
Disable aggressive scrapers or tools - If you are using curl or an automated tool, verify that you are sending a standard user-agent and valid Host header.
If you are the server administrator:
- Check your nginx server block configuration for rules containing return 444;.
- Inspect the access.log and error.log to identify the rule triggering the silent drop.

Source: nginx Documentation - Server Block Configuration