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How does a CDN work, and what does it do?
A content delivery network (CDN) is a resource that helps you provide faster, more reliable page load speeds. As the name implies, a CDN delivers your content through a network of servers located around the world.
There are many CDN providers available; every WordPress.com Website is powered by Jetpack’s, which ensures speedy loading of your images.
A CDN provides your website with access to a reliable network of global servers that are available around the clock. When a site visitor loads your pages, certain static files (images, videos, PDFs) are sent from a server in the network that is nearest to that particular visitor.
Though physical proximity to a server matters for optimal page load speeds, a CDN ensures faster load times if your website attracts more traffic, as your content isn’t being served from a single server in one location.
The primary advantage is consistently optimized page load speeds. Page load times have become increasingly important due to their inclusion as a search engine ranking factor, according to Search Engine Land.
Another significant advantage of CDNs is that your website will be prepared to handle spikes in traffic. Consider a situation in which you receive a link from a popular website, driving thousands of visitors to your site at the same time. If you’re not using a CDN, your site and its content will need to be served by your main hosting server. That’s a heavy load that could slow down or crash your website.
Alternatively, if you’re using a CDN, your site and content will be dispersed across your host and the network of servers within your CDN. With no strain on a single server, your site’s performance won’t lag.
Another advantage is the potential reduction in bandwidth costs, depending on the specifics of your hosting plan.
A CDN is ideal for image loading. Unlike the dynamic elements of your site (your homepage or written posts), images are static. You don’t need the flexibility of having them change; you just need them to load as fast as possible when they’re requested.
Even if you optimize your image sizes before uploading them to your website, you can still strain the server if you have multiple images on your pages — especially if a lot of traffic is coming in.
A CDN improves your site’s image loading times during both slow and peak traffic periods.
If you host your site on any number of web hosts, many elements factor into deciding whether or not a CDN is right for you. There is no simple way to answer “yes” or “no.” Many CDN providers offer free options, so a first step might be to try one out (such as the aforementioned CDN from Jetpack) and then assess how much your image loading times improve.
If your site is on WordPress.com, however, you’re already enjoying optimized image upload speeds thanks to the power of Jetpack’s CDN; you’ll never have to worry about a slow-loading page again. (If you’re not sure WordPress.com is right for you, check out our plans.)