There are two basic caching methods used to speed up websites: server-side caching and edge caching. Although both serve the same purpose, their working principles and effects on performance are quite different. In this article, as HostingServer.com.tr, we explain the differences between edge caching and server caching with concrete examples and numbers.
What Is Edge Caching?
Edge caching stores content on the server closest to the user (CDN edge node). For example, when a user in Istanbul visits your site, the content comes from a CDN server in Istanbul instead of your main server in London. This can reduce latency from 200 ms to 10 ms. Edge caching is ideal especially for static content (images, CSS, JavaScript) and global audiences.
What Is Server Caching?
Server caching, on the other hand, creates static copies of dynamic pages on the web server itself (e.g., with Nginx, Apache, or Varnish). This method reduces server load and serves the same page from cache instead of generating it repeatedly. For example, the WP Rocket plugin for WordPress performs server-side caching. However, this cache exists only on that server; it is not as effective for remote users as edge caching.
Key Differences
- Geographic Proximity: Edge caching stores content on servers physically close to the user; server caching stays at a single point (mostly in a data center).
- Cache Duration: In server caching, TTL (time to live) is usually limited to seconds or minutes, while in edge caching it can be hours or days. For example, a product image can stay in edge cache for 7 days, but only 1 hour on the server.
- Performance Improvement: Edge caching provides an average load time improvement of 50-80% for a global site. Server caching offers a 20-40% speedup, but this advantage diminishes if the user is far from the server.
When to Use Which?
Using both methods together is best. For static content, edge caching should be used; for dynamic content (e.g., pages requiring user login), server caching is preferred. For example, on an e-commerce site, product pages (static) are cached at the edge, while add-to-cart operations (dynamic) are processed on the server. As HostingServer.com.tr, we believe edge caching is critical especially for sites serving a wide geography like Turkey.
Remember: Edge caching is not just a CDN service; when configured correctly, it reduces server load and boosts user experience. Server caching should be your first step.
In conclusion, edge caching and server caching are different but complementary technologies. Striking the right balance according to your project's needs is key to performance and cost optimization. Now take action and test your site's speed!