Published: 18.09.2026
A content delivery network (CDN) is a group of servers around the world that keep copies of your static files close to visitors. Instead of every request going to your origin server, a nearby node answers.
How a CDN works
- A visitor requests an image or a script.
- The nearest CDN node checks its cache.
- If the file is there, it is delivered immediately.
- If not, the node fetches it from your server once, stores it and serves the next visitors from the cache.
Benefits
- Speed: shorter distance means lower latency, especially for visitors far from the server.
- Lower load: the origin server handles fewer requests.
- Traffic savings: bandwidth from your plan is used less.
- Resilience: traffic peaks and many attacks are absorbed by the network.
- Security features: TLS, bot filtering and a firewall are often included.
When you need it
- Your audience is in several countries.
- The site has many images, video or downloads.
- You expect traffic peaks, such as campaigns or sales.
- The origin server is slow or small.
When it is not needed
A local site that serves visitors from one region, with a few pages and a nearby server, gains little.
How to set it up
- Choose a CDN and add your domain.
- Point your DNS (or a static subdomain) to the CDN.
- Configure caching rules and the lifetime of files.
- Check that dynamic and personal pages are not cached.
- Purge the cache after changes to files.
Frequently asked questions
Does a CDN replace hosting? No. It complements the origin server.
Will it hurt SEO? No. A faster site helps rankings.
