Every time a visitor lands on your WordPress website, your server processes the request to build the web page.
To serve a web page, your server starts the PHP engine, queries your MySQL database to retrieve post content and theme settings, executes scripts from your active plugins, and compiles all this information into an HTML page that is displayed in your visitor’s browser.
When hundreds or thousands of visitors browse your site at once, this process repeats constantly. Your server CPU spikes, memory fills up, and your site slows down to a crawl.
This is where full-page caching changes everything.
What Is Full-Page Caching?
Full-page caching can save the final HTML output of a webpage on the first visit. When the next visitor requests that same page, your server delivers the saved HTML file instantly, with no need to query the database or run heavy PHP scripts again.
Think of it like a restaurant menu. Instead of asking the chef to hand-write a new menu for every guest who walks in the door, the restaurant prints copies in advance and hands them out immediately.
Why Many WordPress Caching Plugins Fall Short
Most traditional WordPress caching plugins operate at the application level. When a visitor arrives, WordPress still boots up and runs PHP to check whether a cached copy of the page exists. While this is faster than running database queries, it still forces your server to consume CPU and RAM on every page load.
If your site encounters a traffic spike, an application-level cache can still cause your server to run out of memory. The best way to prevent this slowdown is through server-level caching.
How RunCache Does It Better
If you’re using RunCache, our in-house caching plugin, your server can bypass PHP entirely by taking advantage of caching features provided by the NGINX web server.
When a visitor requests a page that is in the cache, NGINX serves the cached HTML file directly to the browser.
PHP never runs, the database is never contacted, and the page is delivered in milliseconds.
And the best part is that all of this is provided completely free of charge on all WordPress websites without any vendor lock-in. Although RunCache is built by the team at RunCloud, you don’t need to use RunCloud to benefit from RunCache. You can install and use every feature of RunCache completely free of charge on any server, VPS, or cloud hosting provider you prefer.
FastCGI Cache vs. SRCache (Redis): Which One Should You Use?
RunCache gives you two distinct server-level caching engines to choose from: FastCGI Cache and SRCache. Both engines run inside NGINX, which means both options will speed up the website by bypassing PHP execution.
The primary difference lies in where your server stores the cached HTML files:
| Feature | FastCGI Cache | SRCache |
|---|---|---|
| Cache generated by | NGINX | NGINX |
| Storage location | Disk (Server storage) | Memory (Redis RAM) |
| Delivered by | NGINX | NGINX |
| Requires Redis | No | Yes |
In our benchmark tests comparing Redis Full-Page Cache vs NGINX FastCGI Caching, SRCache came out slightly ahead in raw response times and total requests served per second.
However, the difference between the two is very small. Both engines double the number of requests a site can handle compared to an uncached WordPress site, and both deliver rock-solid stability under heavy load.
Our Recommendation
- Choose SRCache (Redis) if your server already uses Redis for object caching or you run a dynamic store such as WooCommerce. Using Redis stores your cache directly in high-speed RAM, ensuring ultra-consistent response times during traffic spikes.
- Choose FastCGI Cache if your server has limited RAM or doesn’t run Redis. FastCGI saves your cached pages directly to disk, keeping your memory completely free for other server tasks.
You can switch between FastCGI and SRCache at any time directly inside the plugin settings to test real-world performance on your site.
Caching WordPress at the Edge with Cloudflare APO
If you bypass PHP processing and serve web pages directly from your NGINX server, then it will definitely speed up your website, but you can take it one step further and bypass NGINX server as well.
When you host your website on a server, it is served from a specific geographic location, and visitors who are physically far from your server will still perceive your website as slow. To solve this problem, you can use global edge networks to speed up your website by serving pages from a data center located near your visitors. This is known as edge caching.
Many third-party plugins charge expensive monthly subscriptions just to connect WordPress to an edge cache. RunCache includes native support for both options completely free of charge.
Method 1: Free Cloudflare Page Caching
If you want enterprise-grade edge delivery without spending extra money, consider using this free Cloudflare integration to manage your cache.
You can easily configure Cloudflare full-page caching in about 10 minutes by following our one-time setup guide inside your WordPress dashboard to connect your Cloudflare API token. Once configured, RunCache automatically purges the edge cache across Cloudflare data centers whenever you publish or update a post.
Since this setup uses standard edge-caching rules, your origin server will still handle a small amount of background processing to check for bypass rules and cache misses, making it a reliable and budget-friendly speed boost.
Method 2: Cloudflare APO Integration
If you already manage a paid domain plan on Cloudflare, you might already have access to Cloudflare Automatic Platform Optimization (APO) without realizing it.
Cloudflare APO is built specifically for WordPress and actively maintains and updates platform-specific caching rules at the edge. This allows their network to serve your entire page layout, fonts, and static assets without requests ever reaching your origin server.
RunCache integrates natively with the Cloudflare APO service to send optimized batch-purge requests whenever you update your website. This delivers maximum server offloading, virtually instant load times worldwide, and zero maintenance overhead for your caching rules. Read our documentation on how to connect Cloudflare APO to RunCache (link this when published https://workover.io/app/projects/2854 ).
How to Set Up RunCache on WordPress
If you host your websites on RunCloud, you can install and configure RunCache with a single click directly inside your RunCloud dashboard. However, you don’t need a RunCloud account to enjoy the speed benefits of server-level caching. You can install RunCache directly on any WordPress site in just a few minutes.
Follow these steps to install and enable RunCache manually:
- Log in to your WordPress administration dashboard.
- Navigate to Plugins > Add Plugin.
- Type “RunCache” into the search bar in the top-right corner.
- Locate the RunCache plugin card and click Install Now.
- Click Activate once the installation finishes.
- Navigate to RunCache in your left sidebar menu.
- Click on the “Full Page Cache” tab.
- Choose your preferred caching engine, then click the toggle switch next to it to turn it on.
That’s it! RunCache will now start caching your webpages and speed up your website. If you want to explore advanced exclusion rules, edge purging, and server settings, read our RunCache Getting Started Guide to learn more.
Final Thoughts
Full-page caching is the single most effective optimization you can make to speed up a WordPress website. Whether you host on a bare-metal server, an affordable VPS, or a managed cloud platform, RunCache provides enterprise-grade caching at no cost.
While RunCache works on any server, configuring NGINX rules, installing Redis, and compiling cache modules manually takes time and technical effort.
Instead, why not streamline your entire hosting workflow by using RunCloud?
When you manage your servers with RunCloud, our platform automatically sets up your NGINX web stack, configures your caching directories, provisions Redis instances, and keeps your server secure with enterprise-grade firewalls. RunCache works seamlessly out of the box on RunCloud servers, delivering top-tier loading speeds for your websites without editing configuration files.
Ready to take your server performance to the next level? Sign up for a RunCloud account today.
Frequently Asked Questions (FAQ)
Will full-page caching break dynamic features like my WooCommerce shopping cart?
Full-page caching can interfere with dynamic shopping carts if your server does not properly exclude checkout sessions and customer cookies. RunCache includes pre-configured exclusion rules for popular platforms like WooCommerce and Easy Digital Downloads right out of the box. If you run a custom checkout solution, navigate to the “Rules” tab in RunCache and add your custom cookie or URL paths to prevent caching on those pages.
Can I use RunCache alongside other optimization plugins, such as WP Rocket or LiteSpeed Cache?
Running multiple full-page caching plugins simultaneously creates file conflicts, unexpected page errors, and unnecessary server load. You should disable page caching in third-party plugins and let RunCache handle your server-level static HTML generation. You can safely keep third-party plugins active if you only use them for asset minification, image optimization, or script deferral.
Does full-page caching replace the need for an Object Cache like Redis?
Full-page caching stores rendered HTML pages for guests, while Object Caching stores database query results for backend operations. If your site has logged-in members or dynamic shopping carts that bypass page caching, an Object Cache keeps those database queries fast. We recommend pairing FastCGI or SRCache full-page caching with a Redis Object Cache to ensure peak performance across your entire website.
Why are visitors still seeing old content even after I purge my server cache?
If your domain routes traffic through a CDN like Cloudflare, the CDN may still hold an older copy of the page at its edge locations. Make sure you enter your Cloudflare API credentials inside the “CDN Edge Cache” tab in RunCache. Once connected, clicking Purge cache in WordPress will clear both your local server cache and your remote Cloudflare edge nodes simultaneously.
Do I need a paid RunCloud subscription to use the RunCache plugin?
You don’t need an active RunCloud account to download and use the RunCache plugin on your WordPress website. The plugin is free to use on any server environment, local development machine, or third-party cloud host. However, pairing the plugin with a RunCloud-managed server provides automated, one-click NGINX configuration and zero-configuration server optimizations.
