How to test your Apache configuration

Testing the Apache configuration before a reload prevents avoidable outages and shortens troubleshooting time. A single typo in a directive can stop the daemon from starting, turning a routine change into an emergency rollback.

The apachectl wrapper runs the underlying Apache binary in validation mode, parsing the main configuration and any included files without replacing the running process. When configuration is split across multiple files, the output typically points to the first file and line where parsing fails, which is the fastest route to a fix.

Examples use the /etc/apache2 layout and the apache2 systemd unit commonly found on Ubuntu and Debian. Some distributions use the httpd binary, different paths (such as /etc/httpd), and a different unit name, so the same validation idea applies but the command names change.

Steps to check Apache configuration:

Open a terminal application.
Open the relevant Apache configuration file in a text editor.
```
$ sudo vi /etc/apache2/apache2.conf
```
Common change points on Debian or Ubuntu include /etc/apache2/sites-available and /etc/apache2/conf-available.

Related: Understanding Apache web server configuration files

Run a syntax check with apachectl.

$ sudo apachectl configtest
AH00526: Syntax error on line 32 of /etc/apache2/apache2.conf:
Invalid command 'ServerNmae', perhaps misspelled or defined by a module not included in the server configuration
Action 'configtest' failed.
The Apache error log may have more information.

Use apachectl -t or httpd -t when configtest is not available.

Note the first reported file and line number from the error output.

Check the Apache error log when the output suggests more details are available.

$ sudo tail --lines=50 /var/log/apache2/error.log
[Sat Dec 13 11:21:10.123456 2025] [core:emerg] [pid 12345] AH00526: Syntax error on line 32 of /etc/apache2/apache2.conf:
Invalid command 'ServerNmae', perhaps misspelled or defined by a module not included in the server configuration
##### snipped #####

On systems that log primarily to journald, use sudo journalctl --unit=apache2 --no-pager --lines=50 and adjust the unit name when it is httpd.

Fix the directive or include file referenced by the error.
Re-run the syntax check until it returns Syntax OK.
```
$ sudo apachectl configtest
Syntax OK
```
Warnings such as AH00558: Could not reliably determine the server's fully qualified domain name do not always fail the test, but setting ServerName removes the noise.
Reload the Apache service to apply the validated configuration.
```
$ sudo systemctl reload apache2
```
On CentOS or Red Hat, the unit is typically httpd (sudo systemctl reload httpd).

A restart drops active connections; use sudo systemctl restart apache2 only when a reload is insufficient.

Related: How to manage the Apache web server service

Verify the service is active after applying the change.

$ sudo systemctl status apache2
● apache2.service - The Apache HTTP Server
     Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
     Active: active (running) since Sat 2025-12-13 11:22:03 UTC; 7s ago
       Docs: https://httpd.apache.org/docs/2.4/
##### snipped #####

Author: Mohd Shakir Zakaria
Mohd Shakir Zakaria is a cloud architect with deep roots in software development and open-source advocacy. Certified in AWS, Red Hat, VMware, ITIL, and Linux, he specializes in designing and managing robust cloud and on-premises infrastructures.

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