How to optimize your WordPress site using server cache? (Varnish – OPcache – Redis -Memcached)

Optimizing the performance of a WordPress site is crucial to ensure an optimal user experience and improve SEO. One of the most effective methods besides caching plugins like WP-Rocket, WP Fastest Cache or W3 Total Cache to achieve this is the use of server caching systems. This article explores best practices for optimizing WordPress sites using server caching plugins, and specifically recommends Varnish, OPcache, Redis and Memcached for optimal performance.

Why Use a Cache System?

A caching system helps reduce the loading time of web pages by storing copies of frequently used files and data. This reduces the load on the web server and improves response speed for users. Here's an overview of the main caching technologies and how they work.

A slow site can lead to an increased bounce rate, decreased time on site, and lower rankings in search engines like Google.

By optimizing your server with powerful caching solutions, you not only improve the user experience, but also your online visibility.

Why is server caching essential for WordPress?

WordPress, while powerful and versatile, can be a huge resource hog on your server. Every request from a visitor triggers a series of operations: accessing the database, running PHP scripts, generating HTML pages, and more. During busy periods, these operations can slow down your site considerably.

Server caching helps overcome this problem by storing static copies of dynamically generated pages and content. Thus, on subsequent requests, the server can provide these copies directly, without having to repeat resource-intensive operations.

The benefits of server caching are multiple

• Significant reduction in page load time
• Improved user experience
• Reduced load on the server
• Natural referencing optimization (SEO)

Server caching solutions for WordPress

1. Varnish: the high-performance reverse proxy
   • Working principle: Varnish acts as an intermediary between your web server and visitors. It caches HTTP responses (HTML pages, images, CSS and JavaScript files) in RAM, allowing them to be served quickly during subsequent requests.
   • Key benefits: Varnish is known for its speed and ability to effectively manage static and dynamic content, making it an ideal solution for high-traffic sites.
2. OPcache: the PHP code accelerator
   • Working principle: OPcache stores precompiled PHP bytecode in shared memory, avoiding the need to recompile the code on each request.
   • Key benefits: OPcache is an essential PHP extension to improve the performance of WordPress sites. It significantly reduces the execution time of PHP scripts.
3. Redis: the versatile in-memory database
   • Working principle: Redis is an in-memory NoSQL database that stores structured data (strings, lists, sets, hash tables, etc.). It offers advanced features such as persistence, replication and transactions.
   • Key benefits: Redis' versatility makes it a powerful tool for complex data caching, user session management, task queues, and many other use cases.
4. Memcached: the distributed object cache
   • Working principle: Memcached is a distributed caching system that stores simple objects (strings, numbers, etc.) in RAM. It is designed to be simple, fast and scalable.
   • Key benefits: Memcached excels at caching loosely structured data and provides excellent performance for both read and write operations.

Comparison table of server cache solutions

Recommendations for optimizing your WordPress site

For optimal optimization of your WordPress site, we recommend the joint use of Varnish, OPcache and Memcached. Varnish accelerates the delivery of static and dynamic content, OPcache optimizes the execution of PHP code while Memcached allows storing objects in memory in a simple and efficient way.

If your site requires more complex data storage or user session management, Redis constitutes an ideal complement.

Video explanation: Varnish, OPcache, Redis and Memcached

Conclusion

Don’t let your slow WordPress site hinder your online success. At Geekworkers, we specialize in WordPress site creation and optimization. Don’t hesitate to contact us for a free, personalized audit of your site. We will help you implement the best server caching solutions for your needs, to ensure an optimal user experience and improved SEO.