AEM always returns 200 status code.

See the following document:

Customizing Pages shown by the Error Handler

Thank you for your response. I tried the custom error handler, but the results are the same. The aem just returns blank page with 200 status code even if the request url is invalid. Not sure what is wrong?

I never got the default 404 not found page working in my local author and publish instances. If the request url is invalid, the response would be a black page with 0 content length, while the HTTP status code is 200. Anyone met with the same problem?

Sorry, a typo. The response is blank page.

Do you see 404.html or 404.jsp in your AEM instance under  /apps/sling/servlet/errorhandler/?

http://localhost:4502/crx/de/index.jsp#/apps/sling/servlet/errorhandler/404.html

yes, I created a 404.html and ResponseStatus.java under /apps/sling/servlet/errorhandler

In the 404.html, the code is as:

<sly data-sly-use.responseStatus="apps.sling.servlet.errorhandler.ResponseStatus">

    <sly data-sly-resource="/content/myproject/en/page-not-found.html"></sly>

</sly>

The code in ResponseStatus.java is:

package apps.sling.servlet.errorhandler;

import com.adobe.cq.sightly.WCMUsePojo;

public class ResponseStatus extends WCMUsePojo { 

    @Override

    public void activate() throws Exception {

        getResponse().setStatus(404);

    }

}

"/content/myproject/en/page-not-found.html" is a custom 404 error page.

That does not look like a deafult behavior. AEM should give you a 404 for non existing nodes:

jbrar-macOS:~ jbrar$ curl -u admin:admin http://localhost:6333/content/geometrixx-outdoors/en/men/pants/fulani-noma -I

HTTP/1.1 404 Not Found

Date: Thu, 29 Aug 2019 21:08:49 GMT

X-Content-Type-Options: nosniff

Set-Cookie: cq-authoring-mode=TOUCH;Path=/;Expires=Thu, 05-Sep-2019 21:08:49 GMT;Max-Age=604800

Expires: Thu, 01 Jan 1970 00:00:00 GMT

Content-Type: text/html;charset=utf-8

Transfer-Encoding: chunked

Can you check if you get the 404 response when running a curl command? If yes, the error handler implementation is wrong

I am not able to get the 404 response when running a curl command to request a non-existent page. Nothing shows up in the terminal, however, I am able to get the correct page for a valid url using curl.

For example, requesting http://localhost:4503/content/myproject/en/search-results shows the html page content, however, requesting http://localhost:4503/content/myproject/en/no-page did not get any response.

I never get a 404 response from the AEM, either in Author or in Publisher. That is very strange.