Choosing a CDN provider
There are a lot more CDN providers than there are cloud service providers (though most of the cloud services providers also offer CDNs). For an art website in particular, but also for any site hosting large assets like big images or videos, which CDN you choose is going to have a major impact on the costs of your website, as you will be charged for the amount of bandwidth you use.
Considerations
There are three many considerations when choosing a CDN: security, configuration, and price.
Security
The companies offering the most 'powerful' CDN solutions also tend to offer WAF (Web Application Firewall) services, which provide a way of securing your website against various common threats and exploits. If you need this, then naturally choosing a CDN that has these offerings is going to make a lot of sense.
Configuration
Some CDN providers offer fairly simple functionality ("simple" here still being fairly advanced), while others have huge amounts of configuration you can apply to your CDN. Depending on your use case, and what you know you need, this can rule out some providers if you need specific things available.
Price
For a lot of websites, this is going to be the overriding consideration. CDN costs vary massively between providers, and for a website hosting large assets like an art website, CDN costs are going to be a very significant part of your outgoings, and likely the biggest.
Before we look at some CDN providers, here is a quick overview of how CDN pricing works.
CDN pricing structure
The general way CDNs are priced is that you are charged per GB you send to users; i.e. all the bandwidth used to send images and other files to your website's visitors. Note that this price is usually different for each world 'region': most CDNs let you choose which regions your CDN will serve traffic from, to let you control the costs somewhat.
There is also frequently a price set for each request made to the CDN for a particular resource, e.g. an image. This number is naturally going to be huge, and so these requests are often priced in big units, e.g. per 10,000 requests or such like.
CDN Providers Overview
This is not an exhaustive list, but a basic overview of some CDN providers at the time of writing.
Amazon CloudFront
Part of AWS. Cloudfront falls squarely into the "powerful but expensive" category; it has a WAF offering, a lot of configuration potential, and extremely good reliability and speed.
Offsetting that is the price - it is one of the most expensive CDNs to use. Here's part of their pricing page as of Dec 8th 2023:
The important price of note here is that bandwidth per GB to the cheapest regions, which is almost always US & EU, is $0.085/GB. While this cost can be offset a bit by using AWS' CloudFront savings bundle (which requires you to pay for 12 months' usage in advance, effectively letting you get a discount on your bill so long as you know you will use at least that much bandwidth), it is still expensive compared to some other providers.
Fastly
Fastly is another "powerful but expensive" provider. Pricing from their website on 8th Dec 2023:
