A CDN, or content delivery network, is a group of servers spread across many countries that store copies of your site's files. When someone visits, the files come from the server closest to them.
Distance still matters on the Internet. If your host is in the US and your reader is in India, every image travels a long way. A CDN shortens that trip.
How a CDN delivers your files
Your hosting server is called the origin. The CDN's servers, often called edge servers, sit in data centers around the world.
The first time a visitor in Mumbai asks for an image, the nearest edge server fetches it from your origin and keeps a copy. The next visitor from that region gets the copy straight from the edge, which is much faster.
It works just like a chain of local warehouses. Instead of shipping every parcel from one central factory, the company keeps stock close to its customers.
Most CDNs cache static files such as images, CSS, JavaScript and fonts. Some can cache full HTML pages too, and many add extras like protection against traffic floods.
Do you need a CDN for WordPress?
Yes, if your visitors come from many countries or your pages carry lots of images. A small local business with nearby visitors may not notice a big difference.
Setting one up is pretty easy:
- First, sign up with a CDN provider. Plenty of them offer a free plan.
- Next, add your domain and follow their setup, which usually means changing your nameservers or adding a DNS record.
- Now, connect it to WordPress through the provider's plugin or your caching plugin, if needed.
- Finally, test your site to make sure every file loads correctly.
After you change your theme's CSS or replace an image, purge the CDN cache too. Otherwise, visitors may keep seeing the old version.
A CDN is one of the killer ways to increase website speed. It can also help you fix the "Use cookie-free domains" warning.
Remember, a CDN does not replace good hosting, but it makes a good site feel faster everywhere. Share your experience with CDNs in the comments below.