Nginx vs Apache for WordPress: A Linux Expert‘s In-Depth Comparison

Introduction

Choosing the right web server is a critical decision when deploying a WordPress site. It has major implications on your site‘s performance, scalability, security, and feature set. The two leading open source options – Nginx and Apache – are both capable of running WordPress. But they each have distinct characteristics that make them better suited for different use cases.

In this comprehensive comparison, we‘ll dive deep into the key differences between Nginx and Apache from the perspective of a Linux and proxy server expert. We‘ll analyze performance benchmarks, explore advanced configuration options, and examine real-world use cases. By the end, you‘ll have an expert-informed opinion on whether Nginx or Apache is the best fit for your WordPress site.

Nginx vs Apache: Fundamental Architecture Differences

At their core, Nginx and Apache have very different architectures for handling web requests. Understanding these structural differences is key to evaluating their performance and scalability.

Apache uses a process-based model, spawning a separate thread for each simultaneous connection. While more efficient than forking a new process per request, Apache‘s approach can still lead to significant memory usage at high concurrency. Each thread requires its own memory space, so the total RAM consumed scales linearly with the number of connections.

In contrast, Nginx was built from the ground up as an event-based, asynchronous web server. A single Nginx worker can handle thousands of concurrent connections in a non-blocking fashion. Requests are processed in a highly efficient run-loop within each worker. As a result, Nginx maintains consistently low memory usage even under intense load.

To illustrate this difference, let‘s look at some data from a WordPress benchmark test conducted by Kinsta:

Metric	Nginx	Apache
Requests per second	18509	6549
99th percentile (ms)	162	3550
Errors	0	79

Source: Kinsta

As you can see, Nginx was able to serve nearly 3 times as many requests per second as Apache in this test of a realistic WordPress installation. Nginx also maintained much better response times at the 99th percentile and avoided any errors, while Apache‘s performance degraded under load.

This is just one benchmark, but it exemplifies the performance advantage Nginx typically has over Apache when serving WordPress under high traffic conditions. Apache can be tuned to handle higher concurrency with tools like mpm_event or PHP-FPM, but Nginx pulls ahead for raw speed.

Configuring Nginx and Apache for WordPress

Of course, WordPress doesn‘t run "out of the box" on either web server. Some additional configuration is necessary to get optimal WordPress performance and security. Let‘s step through the key config optimizations for each server.

Nginx WordPress Config

Here are the essential components of a performance-optimized Nginx config for WordPress:

server {
    listen 80;
    server_name example.com;
    root /var/www/example.com;
    index index.php;

    # Gzip compression
    gzip on;
    gzip_types text/css application/x-javascript text/x-component text/richtext image/svg+xml text/plain text/xsd text/xsl text/xml image/bmp application/java application/msword application/vnd.ms-fontobject application/x-msdownload image/x-icon;

    # Nginx microcaching
    fastcgi_cache_path /tmp/nginx_cache levels=1:2 keys_zone=WORDPRESS:100m inactive=60m; 
    fastcgi_cache_key "$scheme$request_method$host$request_uri";
    add_header X-Cache $upstream_cache_status;

    location / {
        try_files $uri $uri/ /index.php?$args;        
    }

    location ~ \.php$ {
        fastcgi_pass unix:/run/php/php7.4-fpm.sock;  
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

        # Enable microcaching for PHP     
        fastcgi_cache WORDPRESS;
        fastcgi_cache_valid 200 60m;
    }

    # Deny access to sensitive files
    location ~* \.(log|ini|conf)$ {
        deny all;
    } 
}

This config includes several key performance optimizations:

• Gzip compression is enabled for common web file types
• FastCGI microcaching is configured with a 100MB memory zone and 60 minute timeout
• The try_files directive efficiently maps URLs to WordPress permalinks
• PHP requests are passed to PHP-FPM over a Unix socket
• Access is denied to potentially sensitive files like logs and configs

With this Nginx WordPress config in place, you can expect fast and efficient performance, especially for mostly static WordPress pages.

Apache WordPress Config

Now let‘s look at an optimized Apache config for WordPress:

<VirtualHost *:80>
    ServerName example.com
    DocumentRoot /var/www/example.com

    <Directory /var/www/example.com>
        AllowOverride All
        Require all granted
    </Directory>

    # gzip compression
    AddOutputFilterByType DEFLATE text/plain
    AddOutputFilterByType DEFLATE text/html
    AddOutputFilterByType DEFLATE text/css  
    AddOutputFilterByType DEFLATE application/javascript

    # Browser caching
    ExpiresActive On
    ExpiresByType image/jpg "access 1 year"
    ExpiresByType image/jpeg "access 1 year"
    ExpiresByType image/gif "access 1 year"
    ExpiresByType image/png "access 1 year"
    ExpiresByType text/css "access 1 month"  
    ExpiresByType application/javascript "access 1 month"

    # Deny access to sensitive files
    <FilesMatch "\.(log|ini|conf)$">
        Require all denied
    </FilesMatch>
</VirtualHost>

Some notable optimizations here for Apache:

• Gzip compression is enabled using the modern filter syntax
• Browser caching is configured with the expires module for common static assets
• Access is denied to sensitive file types with FilesMatch

While not as sophisticated as the Nginx config in terms of microcaching, this Apache config will still deliver solid WordPress performance. The main caveat is that Apache may struggle with high concurrency, whereas Nginx will scale more smoothly.

Use Cases: When to Choose Nginx or Apache

So given the performance differences and configuration nuances, when should you opt for Nginx vs Apache? Here are some common use cases and recommendations:

Choose Nginx if:

• You expect very high traffic and need maximum scalability
• You want the absolute fastest possible WordPress performance
• You‘re using WordPress as a decoupled CMS with a static frontend
• You don‘t have any Apache-specific requirements

Nginx is simply going to be faster and more resource-efficient for high-scale WordPress deployments. It‘s no coincidence that WordPress.com, one of the largest WP platforms in the world, uses Nginx.

Choose Apache if:

• You have existing .htaccess configurations that would be difficult to migrate
• You rely on Apache modules like mod_security or mod_evasive
• Your WordPress site doesn‘t justify the added complexity of Nginx
• You want the "boring" and battle-tested option

There‘s something to be said for familiarity, and Apache has been a staple of the WordPress ecosystem for decades. For low to medium traffic sites, the performance difference may not be worth the migration effort.

Real-World Benchmarks and Case Studies

We‘ve covered a lot of theory in comparing Nginx vs Apache for WordPress. But what do the performance numbers look like in the real world? Let‘s examine some case studies and benchmarks.

In a large-scale load test of WordPress 5.5 conducted by Dellemc, Nginx demonstrated a significant performance advantage over Apache:

Metric	Nginx	Apache
Throughput (req/sec)	6275	3674
Latency (ms)	15.8	27.1
99% Latency (ms)	26.3	90.8
CPU Usage (%)	28	87

Source: Dellemc

In this test, Nginx was able to serve 70% more requests per second than Apache, while maintaining 42% lower latency. Just as importantly, Nginx consumed only a fraction of the CPU resources. At the 99th percentile, Nginx‘s response time was 3.5X faster than Apache‘s.

But what about a real-world migration? Smashing Magazine shared their experience moving from Apache to Nginx way back in 2011:

We got about 70 million page views a month…After switching articles to Nginx (still powered by WordPress), the server load didn‘t go above 0.5. The average memory usage on that particular server has dropped from 13 GB to around 7 GB. Performance and stability have significantly improved.

Source: Smashing Magazine

While an older anecdote, this migration demonstrates the dramatic impact Nginx can have on heavily trafficked WordPress sites. Cutting memory usage nearly in half is a huge win.

Of course, these benchmarks don‘t tell the whole story. WordPress performance depends on many factors beyond just the web server, like caching plugins, database optimization, and hosting specs. But in general, Nginx will provide better performance for WordPress sites compared to a similarly-tuned Apache setup.

Conclusion

In the battle of Nginx vs Apache for WordPress hosting, Nginx emerges as the clear performance champion. Its event-driven architecture and lightweight resource usage make it the superior choice for high-traffic WordPress deployments.

However, Apache still has a significant place in the WordPress ecosystem. Its rich feature set, .htaccess support, and legacy compatibility mean it remains a suitable choice for many WordPress sites.

As a Linux and proxy server expert, my recommendation is to use Nginx for WordPress if you:

1. Anticipate scaling to high traffic levels
2. Want to maximize WordPress performance
3. Are starting a new project without Apache dependencies

Stick with Apache if you:

1. Have existing .htaccess rules or Apache-specific customizations
2. Need features like built-in authentication or caching that Apache provides
3. Don‘t expect to scale beyond moderate traffic levels

Regardless of which web server you choose, the most important factor is proper configuration. An optimized Nginx or Apache setup can make a significant difference in WordPress performance and resource usage. Invest the time to understand your web server‘s settings.

Ultimately, Nginx and Apache are both powerful tools in the WordPress stack. With the right setup and optimizations, they can each help deliver a fast and reliable WordPress experience. Choose the server that aligns with your priorities and constraints.