Server-Side caching Vs. Cache Plugin In WordPress

Caching basically means saving requests for faster performance in the future – Various layers, protocols, and services are involved in WordPress caching.

The caching capabilities in WordPress involve different layers, methods, and tools with multiple configurations – For example:

Server-side Caching: That means the server generates the cache – the technique is old, but it’s convenient for handling a lot of traffic. Examples include LiteSpeed cache, FastCGI, Nginx proxy, and other web host cache layers. Also, most server caching supports full-page caching.
Object Cache: This is perfect for dynamic sites or sites with a lot of backend activity. Object caching saves database requests in RAM, reducing the number of requests – Memcache, Redis, etc.
Software-Level: WordPress cache plugins usually use PHP to serve cache.
However, they aren’t as fast as true server caching, but they’re still really useful, especially since some of them have extra features.
CDN: Caching at the edge is progressing so fast – it used to be just for static assets from CDNs, but now it is caching even full pages.

Choosing the right caching option for WordPress is VERY important, as making a mistake could result in your site being slower than expected.

Server-Side Caching In WordPress

In WordPress, many PHP functions and database commands are run when you receive a request. The server manages considerable queries when someone opens a page or post (depending on the template, functions, and plugins).

Some queries may take considerable milliseconds to complete if you have a lot of data in your database. All these PHP and database requests add to the load time, which can take a while.

That is one reason your website receives a poor Time to First-byte, even for nearby locations. However, server-level caching speeds up this procedure by caching copies of the HTML file on the server.

Results in a decrease in TTFB and less resource usage for the server, so the server only needs to serve that file. The purpose is to speed up future requests by temporarily storing data. There are different types of server-side caching for web servers, such as Nginx (FastCGI), LiteSpeed (LS Cache), Varnish, etc.

Some WordPress host providers and cloud hosting control panels implement server caching functionality.

LiteSpeed, Nginx, and Apache web servers — Apache | LiteSpeed | Nginx

Modern WEB hosts claim you do not need to use cache plugins since they have implemented server-level caching. Also, fully managed hosts such as WP Engine, Kinsta, EasyWP, and PressLab don’t allow cache plugins.

The difference between static and dynamic content also affects caching. Static content, such as graphics, stylesheets, and JavaScript, does not need to be updated very often and is cached most of the time.

However, dynamic content, such as HTML elements, shopping carts, and associate profiles that change based on user behavior, is more complicated.

Approaches such as Cloudflare APO and QUIC.cloud can cache dynamic content with full-page caching. QUIC.cloud, Rocket.net, and FlyingCDN all support full-page caching, even with critical elements.

Here are some edges and drawbacks of server-side caching:

Pros:

Improved server performance: The server only spends a little time getting the same content. Storing query results significantly reduces database search measures. Keeps your server free of clutter by caching. Cached content reduces the workload for data-intensive content.
Improved page load speed: Cache-served pages reduce load times, and users get a smooth experience even during high traffic.
Page Caching: Using server-side helps reduce server load on websites with dynamic content. Some hosting, like rocket.net, supports full-page caching and significantly reduces response time on dynamic websites.
Server stability: A lower server load means fewer crashes and downtimes. Helps your website improve and handle more traffic without slowing down – handle large numbers of visitors.

Cons:

Slow to regenerate: Cached pages take a long time to regenerate after being cleared at the server level. Even with LiteSpeed cache, there is no option to preload the cache.
Issues with dynamic content: Dynamic content is updated regularly in response to user interaction or live. Contains individualized details like your preferred items and profile details. This type of content doesn’t work with traditional caching methods since they treat all requests equally.
Lack of front-end optimization: Usually, server-side caching caches content according to configurations, but cache plugins provide more edges in speeding up your website due to front-end optimizations.
It isn’t easy: Requiring a more detailed analysis of cache settings.

Several modern web hosts, such as Rocket.net, utilize Cloudflare Enterprise for cloud caching, but Cloudflare can also cache HTML pages, which works much like a server-side cache. What if that’s not enough?

In that case, it would be more advantageous to use a cache plugin since most plugins generate HTML pages in the same manner as on the server side. You can do more front-end optimizations with cache plugins than server LEVEL.

Using only caching layers will only serve to cache your website, but plugins can make it more powerful and can also re-generate cache pages quickly.

When you pick WP themes, make sure they’re not too heavy because heavy themes can cause issues with caching. LiteSpeed already has caching.

If you are using Nginx, you can use FastCGI. Varnish or cache plugins are great options if you’re using Apache. You can use the WordPress cloud hosting control panel to access cloud hosts like Vultr. Some platforms, like SpinupWP, have in-built server caching features that server full-page cache mechanism.

WP Plugins For Server-Level Caching

LiteSpeed Cache: With millions of installations, LiteSpeed Cache has the finest reputation among WordPress plugins. Caching on the server gives it a lot of benefits. Officially supporting full-page caching at EDGEs with QUIC.cloud CDN. PLUS, it’s a completely free plugin for LiteSpeed.
SiteGround Optimizer: This is an official SiteGround cache plugin. It supports both server-level cache and dynamic cache – however, it has several critical issues that SiteGround still needs to address.
Breeze: designed for Cloudways’ hosting environment. It does not support dedicated server caching like LSC, but it does support the Varnish caching option, designed for Cloudways servers.
RunCloud Hub: settings for Redis full-page caching and FastCGI-proxy page caching if you use the RunCloud panel.
Aruba Cache: It’s only compatible with Aruba hosting.

Cache Plugins

Besides server level caching, developers created WordPress caching solutions
for users without server access. Cache plugins typically generate HTML pages similar to the server cache. All web servers support PHP caching via plugins. However, some plugins are ideal for LiteSpeed or Apache but not for Nginx.

Some developers, however, say that, for high-traffic websites, server-level caching is more suitable than plugins because file-based caching requires more server resources to generate HTML pages.

Even if you use LiteSpeed hosting, you can use another plugin instead of LSC. Also, most plugins do not support full-page caching.

Most of the time, it does not matter whether the caching is done at the file-based or server levels since if your hosting provider adds server-side caching facilities, you can still use cache plugins for other optimizations.

For example, the FlyingPress plugin offers more than 30 optimizations in addition to caching. Here are some benefits of using the cache plugin:

Simple Caching Process: In most cases, cache plugins generate HTML pages in the same manner as server-side caching. However, cache plugins can modify the front end more effectively than the server level.
Cache Preload: This function is much more convenient with plugins than server-side since they can automatically preload (regenerate) the cache immediately or based on set time intervals.
Lazy loading: Images, videos, and even some CSS elements can be lazy-loaded by modern plugins.
CSS Optimization: Features include generating critical CSS, removing rendered-blocking scripts, and minifying CSS.
Javascript Optimization: Many plugins provide features such as Defer JavaScript, Minify, Defer inline, etc.
Localizations: Plugins have features such as font localization, gravatar, and other third-party resources.

Over the past few years, I have tried over 20 cache plugins. The good ones have valuable features, are easy to use, and keep your site undamaged.

You might prefer aggressive plugins with many front-end optimizations if you manage only a few sites. You’ll obviously want a less-featured plugin if you manage multiple websites. Using a good WordPress CDN provider is also essential, as CDN caching occurs at the server level.

Object Caching

If your site has tons of calculated data and statistics in the admin backend or constantly refreshes data, object caching suits you.

Object caching saves the database calls in RAM, so they don’t have to be retrieved every time. You don’t need OC if you just have a static website.

To Conclude

Previously, caching was handled solely by web servers. With so many requests, servers can overload, causing slow response times and failures.

Caching on the server is ideal for sites with a lot of traffic because it lets them handle a lot of visitors at once. Also, caching improves page speed and can be used even on small web servers.