What Is Apache Web Server? A Basic Look at What It Is and How It Works

Apache is a popular open-source, cross-platform web server that is, by the numbers, the most popular web server in existence. It’s actively maintained by the Apache Software Foundation.

Some high-profile companies using Apache include Cisco, IBM, Salesforce, General Electric, Adobe, VMware, Xerox, LinkedIn, Facebook, Hewlett-Packard, AT&T, Siemens, eBay, and many more (source).

In addition to its popularity, it’s also one of the oldest web servers, with its first release all the way back in 1995. Many cPanel hosts utilize Apache today. Like other web servers, Apache powers the behind-the-scenes aspects of serving your website’s files to visitors.

Because Apache doesn’t perform as well in some benchmarks, especially for static websites or websites with high traffic, Kinsta uses the NGINX web server instead of Apache. Though NGINX hasn’t been around for as long as Apache, it’s quickly grown in popularity and market share since its launch in 2004.

How Does Apache Work? Web Server Basics Explained

While there’s a lot of complexity underpinning how a web server functions, the basic job of all web servers is to accept requests from clients (e.g. a visitor’s web browser) and then send the response to that request (e.g. the components of the page that a visitor wants to see).

The Apache web server has modules which add more functions to its software, such as MPM (for handling multi-processing modes) or mod_ssl for enabling SSL v3 and TLS support (suggested reading: TLS vs SSL). Some common features seen in Apache include:

• .htaccess
• IPv6
• FTP
• HTTP/2
• Perl, Lua, and PHP
• Bandwidth throttling
• WebDAV
• Load balancing
• URL rewriting
• Session tracking
• Geolocation based on IP address

While a web server is an essential part of any website, it’s important to note that casual WordPress users are unlikely to interact with their web server directly most of the time.

Apache vs Nginx Usage Stats

When you look at every single website on the Internet, Apache is the most popular web server. It powers 47% of the websites with a known web server, according to W3Techs.

However, Apache’s usage greatly drops when you start looking at the web’s most highly trafficked sites. Apache only powers:

• 27.1% of the 100,000 most popular sites
• 21.5% of the 10,000 most popular sites
• 16.2% of the 1,000 most popular sites

This drop-off likely stems, at least in part, from Apache’s lower benchmarks for high traffic websites.

Conversely, NGINX, the web server that Kinsta uses, is used by a majority of high-traffic sites, powering:

• 56.1% of the 100,000 most popular sites
• 63.2% of the 10,000 most popular sites
• 57% of the 1,000 most popular sites

If you check the Google Search trends since 2004, you can see this trend play out where Apache’s popularity (as a search term) is decreasing while NGINX’s is creeping up.

How To Check Which Web Server You’re Using

If you want to see whether you’re using Apache or NGINX, you can often (but not always) look at your site’s HTTP header.

To view your site’s HTTP header, you can:

• Use the Network tab of Chrome Developer Tools
• Use a tool like Pingdom or GTmetrix

This method may not work if you’re using a service like Cloudflare, though.

Apache and the Apache feather logo are trademarks of The Apache Software Foundation.