Server Cache vs. Browser Cache vs. Site Cache: What’s the Difference?

Slow websites lose visitors. If your store or site takes more than a couple of seconds to load, people leave – and they don’t come back.

That’s where caching comes in.

In this guide, we’ll break down the three main types of website caching:

• Server cache
• Browser cache
• Site (or page) cache

You’ll learn what each one does, how they work together, and why they matter for speed and stability. We’ll also show how tools like RunCloud Hub for WordPress make it easier to manage caching without diving into server configs.

Let’s get into it.

What is Caching?

When a server handles a request, it often needs to process multiple database queries and calculations before responding. This works fine for occasional access, but with repeated requests, it wastes time and server resources by doing the same work repeatedly.

Caching speeds up performance by storing copies of frequently used data in fast-access memory. Instead of regenerating the same content on every request, the server or browser checks the cache first and serves the stored version if available.

On websites, this cached data can include anything from images and stylesheets to entire web pages or database query results.

📖 Suggested read: nginx Caching for WordPress – Complete Guide & Tutorial

What is Server Cache?

Server cache refers to various caching mechanisms implemented directly on the web server or dedicated caching servers in front of the origin server. This type of caching reduces the server’s processing load by storing the results of computationally expensive operations or frequently requested content.

For instance, if generating a dynamic web page requires multiple database queries and complex calculations, the server can cache the final HTML output of that page.

When another user requests the same page, the server can deliver the pre-generated cached version almost instantly, without re-executing all the backend processes.

Other examples of server caching include opcode caching (storing precompiled script code), object caching (storing frequently used data objects like database query results), or CDN caching (where geographically distributed servers cache static assets closer to users). This significantly improves the server’s capacity to handle more traffic and delivers content faster.

With RunCloud, you can enable server-side caching quickly by installing RunCloud Hub, which includes powerful options like FastCGI and object caching for WordPress.

Read more about caching in our blog post titled How to Easily Optimize Your WordPress Website With RunCloud Hub. 

📖 Suggested read: Which is Better: Redis Full-Page Cache or nginx FastCGI Caching?

What is Browser Cache?

Browser caching helps speed up return visits to a site by storing common files, like logos, styles, and scripts, directly in the user’s browser. Instead of downloading them again every time, the browser loads them from local storage.

This process dramatically speeds up page loading times for subsequent visits because fetching files from local storage is much faster than retrieving them online. It also reduces bandwidth consumption for both the user and the web server.

Website administrators can influence browser caching behavior by setting appropriate HTTP headers (like Cache-Control and Expires) on their server responses, telling browsers how long they should keep specific files cached.

📖 Suggested read: Everything You Need to Know About WordPress Object Caching

What is Site Cache (Page Cache)?

Site cache, often called page cache, is a type of server-side caching that stores fully rendered HTML pages. When a user requests a page, instead of the server dynamically generating it by querying databases, processing templates, and running scripts every single time, it can serve a static HTML copy directly from the cache. This approach is particularly beneficial for content that doesn’t change frequently for every user, such as blog posts, product pages, or informational pages.

For example, if a popular news article is requested, the server might generate it once, store the complete HTML page in its cache, and then serve that same static file to thousands of subsequent visitors. This bypasses almost all server-side processing, leading to incredibly fast load times and significantly reducing server resource usage.

📖 Suggested read: How to Use Redis Full-Page Caching to Speed Up WordPress

Server Cache vs. Browser Cache vs. Site Cache: Key Differences

Here’s how the three main types of cache compare, based on what they store, where they’re kept, and how they help your site perform better:

📖 Suggested read: The Best WordPress Caching Plugins To Speed Up Your Site (2025)

Which Cache Type is Best for WordPress?

For WordPress sites, page caching (also called site caching) usually gives the biggest performance boost. WordPress dynamically builds each page by running PHP scripts and querying the database, even for content that doesn’t change. Page caching skips all that by storing a fully rendered HTML version of the page and serving it instantly.

This alone can cut load times dramatically.

Browser caching is another must-have. It stores static assets, like logos, stylesheets, and scripts, directly in the visitor’s browser. That means repeat visits feel faster, and your server uses less bandwidth.

For high-traffic or more dynamic sites, you can go further by enabling object caching – a type of server cache that stores the results of frequent database queries in memory using tools like Redis or Memcached. This reduces the load on your database and speeds up dynamic page generation.

When used together, these caching layers improve speed, reduce server resource use, and keep your site stable under load.

📖 Suggested read: LiteSpeed Cache WordPress Plugin Configuration Tutorial

When Should You Use Each Type of Cache?

• Use browser caching on all websites to store static assets – logos, stylesheets, JavaScript, and fonts – that rarely change. This significantly speeds up page loads for returning visitors and reduces server bandwidth.
• Server cache (in various forms) is essential for any dynamic website to reduce server load and improve user response times.
• Use page cache (a type of site cache) for frequently accessed pages that are identical or very similar for most users, such as blog posts, informational pages, or product category pages.
• For highly dynamic elements or user-specific content (like a shopping cart or personalized dashboard), more granular server caching, like object caching (for database query results) or fragment caching (for parts of a page), is more appropriate to avoid serving stale or incorrect personalized data.

📖 Suggested read: 9 Redis Alternatives Worth Keeping an Eye On

Final Thoughts

Caching helps your site handle more traffic without increasing server resources. Each type of cache has a specific role, and together, they create a faster, more efficient user experience. 

For WordPress users, caching setup can feel complex.

RunCloud Hub simplifies it by handling server-side caching (like FastCGI) automatically, with smart cache purging whenever content is updated.

When a visitor requests a page, if a cached version exists at the server level, it’s served directly by nginx before WordPress loads or processes PHP and database queries. This bypasses the most resource-intensive parts of WordPress page generation, resulting in dramatically faster load times for your visitors.

RunCloud streamlines the setup and management of these powerful caching mechanisms and allows you to focus on creating great content while we optimize performance. Furthermore, RunCloud intelligently interacts with WordPress to know when content is updated, so it can purge the old cache and serve fresh content, ensuring accuracy.

Caching doesn’t have to be technical. With RunCloud Hub, you can enable server, page, and object caching in just a few clicks – no manual config needed.

If you want your site to load faster, handle more traffic, and use fewer resources, start using RunCloud today.

FAQs on Caching

What is the difference between caching and compression?

Caching stores copies of frequently accessed data (e.g., web pages, images) to serve them quickly on subsequent requests, reducing server load and latency. Compression, on the other hand, reduces the file size of data before it’s transmitted, making downloads faster by using less bandwidth.

Does caching improve SEO rankings?

While caching isn’t a direct ranking factor, it significantly improves website speed and user experience, which are crucial for SEO. Faster load times can lead to lower bounce rates and better engagement, directly impacting search engine rankings.

How do I know if my cache is working?

You can use your browser’s developer tools (Network tab) to inspect HTTP response headers like Cache-Control, Expires, or X-Cache status, which tells if a resource was served from cache. Alternatively, online cache-checking tools or observing significantly faster load times on a second page visit can also confirm its operation.

What happens if I disable caching?

Disabling caching means every user request will fetch fresh data directly from your origin server, significantly increasing page load times and server resource consumption. Increased processing and bandwidth usage can lead to a slower user experience and potentially higher hosting costs.