CDN Cache
PerformanceCDN Cache is a content delivery network feature that stores copies of website assets on geographically distributed edge servers so visitors can download them from a nearby location. By serving cached files instead of repeatedly fetching them from the origin server, it reduces latency, lowers bandwidth usage, and helps absorb traffic spikes. Cache behavior is controlled by rules, headers, and purge mechanisms.
How It Works
A CDN cache sits between visitors and your origin hosting server. When someone requests a file (an image, CSS, JavaScript, video segment, or even an HTML page), the CDN checks whether it already has a fresh copy at a nearby edge location. If it does, the CDN returns that cached copy (a cache hit). If not, it retrieves the file from the origin, stores it for future requests, and then serves it (a cache miss).
Whether an object is cached and for how long is governed by cache-control headers (such as Cache-Control and Expires), CDN rules, and sometimes query-string or cookie handling. Time-to-live (TTL) defines how long an item is considered fresh before the CDN revalidates it with the origin. When content changes, you can purge or invalidate cached objects so edge servers fetch the updated version. Many setups also use versioned filenames (for example, app.abc123.js) to avoid serving stale assets.
Why It Matters for Web Hosting
CDN caching can make a modest hosting plan feel faster by offloading repeated requests for static files and reducing the work your origin server must do. When comparing hosting plans, consider whether the provider supports easy CDN integration, proper header control, and cache purging, because misconfigured caching can cause outdated pages, broken logins, or inconsistent behavior across regions. For performance-focused sites, CDN cache is often a key part of meeting speed and uptime expectations during traffic spikes.
Common Use Cases
- Caching static assets like images, fonts, CSS, and JavaScript for faster global delivery
- Reducing origin bandwidth and CPU load on shared hosting or small VPS plans
- Improving performance for international audiences by serving content from nearby edge locations
- Handling flash traffic (campaigns, product drops, news mentions) by absorbing repeated requests at the edge
- Accelerating media delivery such as video segments, downloads, and large files
CDN Cache vs Browser Cache
CDN cache stores content on edge servers shared across many visitors, reducing distance and load on your origin hosting. Browser cache stores content on an individual users device, reducing repeat downloads for that same user. In practice, they complement each other: CDN caching speeds up first-time and global requests, while browser caching improves repeat visits. Both rely on cache headers, but CDN cache also needs purge/invalidation workflows to keep edge copies current.