How to Install Apache HTTP Server on Ubuntu

Install Apache HTTP Server on Ubuntu with APT, verify the service, test localhost, and troubleshoot common installation problems.

Apache HTTP Server is software that accepts HTTP requests and returns web resources such as HTML pages, CSS files, images, and other content. Ubuntu provides Apache through the apache2 package.

A browser and a web server have different roles: the browser requests a page, while Apache receives the request and delivers the page. For background, see what a web server does and what Apache HTTP Server is.

Prerequisites

A working Ubuntu installation with network access to configured Ubuntu package repositories.
A terminal session.
An account permitted to run administrative commands with sudo. sudo runs a command with elevated privileges.
No other service using the standard HTTP port, port 80, if Apache is expected to listen there.

Ubuntu is a Linux distribution that uses APT, its package management tool and package ecosystem. A package repository is a configured source from which APT obtains package metadata and software packages.

Refresh and upgrade Ubuntu packages

Before installing software, refresh APT's package metadata. This downloads current information about available package versions; it does not itself install upgrades.

sudo apt update

You can then apply available upgrades to already-installed packages:

sudo apt upgrade

APT may ask you to confirm the operation. Review the proposed changes and enter Y when you want to continue. To perform both operations in sequence, use:

sudo apt update && sudo apt upgrade

Install Apache with APT

Install the Ubuntu Apache package named apache2:

sudo apt install apache2

APT downloads Apache and any required dependencies from the configured package repositories. If APT asks for confirmation, enter Y and press Enter to proceed.

The package installation normally enables Apache to start during system boot and starts the Apache service immediately. A service is a background process managed by the operating system; Apache runs as a service named apache2.

Check that the Apache service is running

Modern Ubuntu releases use systemd to manage services. The primary status command is:

sudo systemctl status apache2

Look for a result such as Active: active (running). This indicates that the service started successfully. The status view may open in a pager; press q to exit.

You can also check whether Apache is enabled to start automatically at boot:

sudo systemctl is-enabled apache2

The traditional service interface is an alternative status check:

sudo service apache2 status

Test the local Apache website

Open a browser on the same Ubuntu computer and visit http://localhost/. localhost is a hostname that refers to the computer currently being used, so this test checks the local Apache listener rather than a remote server.

A successful installation normally displays the Ubuntu Apache default page. Seeing that page confirms that Apache is installed, running, listening for HTTP requests, and serving its default site.

You can test the HTTP response without a browser by using curl:

curl -I http://localhost

The -I option requests response headers. A response containing an HTTP status such as 200 OK is evidence that Apache answered the local request.

Installation commands and expected results

Step	Command	Purpose	Expected result
Refresh package metadata	`sudo apt update`	Obtain current information about packages in configured repositories.	Repository metadata is downloaded without an unresolved error.
Upgrade installed packages	`sudo apt upgrade`	Apply available updates to installed packages.	APT lists upgrades and may request confirmation.
Install Apache	`sudo apt install apache2`	Download and install Apache and its dependencies.	The `apache2` package is installed; the service normally starts and becomes enabled.
Check service status	`sudo systemctl status apache2`	Inspect the Apache service.	The status includes `active (running)` when startup succeeded.
Test local HTTP response	`curl -I http://localhost`	Send a local HTTP request without a browser.	Apache returns HTTP response headers, commonly including `200 OK`.

Common problems and troubleshooting

Symptom	Likely cause	How to check	Resolution
APT cannot download packages	No network connection, incorrect repository configuration, or a temporary repository problem.	Confirm network connectivity, then run `sudo apt update` again and read the repository error.	Restore connectivity or correct the configured Ubuntu package sources before retrying.
Apache is not active	A configuration error, port conflict, failed dependency, or another startup condition.	Run `sudo systemctl status apache2`. For service logs, run `sudo journalctl -u apache2`.	Resolve the reported error, then start or restart Apache with `sudo systemctl start apache2` or `sudo systemctl restart apache2`.
`localhost` does not load	Apache is stopped, the URL or browser proxy is unexpected, or Apache is not listening on the expected port or interface.	Check service status, run `curl -I http://localhost`, and inspect port 80 listeners.	Start Apache and address the listener, URL, or browser configuration issue identified by the checks.
Apache fails because port 80 is already in use	Another web server, development server, or old Apache process occupies port 80.	Run `sudo ss -ltnp \| grep ':80'` to identify the listening process.	Stop or reconfigure the conflicting service, or intentionally change Apache's listening port.
Apache works at localhost but not from another computer	An Ubuntu firewall, cloud or network firewall, or interface binding prevents remote access.	Confirm local access first; then check host and upstream firewall rules and inspect Apache's listener configuration.	Allow HTTP traffic where appropriate and ensure Apache listens on the intended network interface.

Port 80 conflicts

Port 80 is the standard TCP port for unencrypted HTTP traffic. If another process already owns it, Apache may install successfully but fail to start. Identify the process before stopping anything:

sudo ss -ltnp | grep ':80'

Do not stop an unknown service blindly. Determine whether it is another web server, a development server, or an older Apache process, then stop or reconfigure it when appropriate.

Important Apache paths and next steps

The default document root is /var/www/html. A document root is the directory containing the files served by a website. After installation, Apache serves its default site from this location.

Main Apache configuration: /etc/apache2/apache2.conf
Default site configuration: /etc/apache2/sites-available/000-default.conf
Default document root: /var/www/html

To host a custom site, place suitable content in a document root and, when more than one site is needed, configure a virtual host. Continue with Apache configuration files, the default virtual host, or creating a new virtual host.

Production or network-facing servers also require deliberate firewall rules, HTTPS, updates, permissions, and security hardening. Useful follow-up subjects include configuring SSL, Apache access and error logs, and the ports configuration file.

Exam-relevant summary

Ubuntu's Apache package and service name is apache2.
Use sudo apt update to refresh package metadata and sudo apt upgrade to apply available package upgrades.
Install Apache with sudo apt install apache2.
Use sudo systemctl status apache2 and look for active (running).
Test the local server at http://localhost/ or with curl -I http://localhost.
The default document root is /var/www/html, and port 80 is the normal HTTP port.