CDN Pricing Models
The Main CDN Pricing Models
CDN pricing describes how a provider charges for delivering your content. Most providers combine a few common models, and the mix you pay depends on your traffic and the features you use. Rates change over time, so this article describes the structures rather than quoting figures. Push-based storage services often bill differently from pull-based ones, as explained in pull CDN vs push CDN.
- Per gigabyte of transfer. You pay for the volume of data sent to visitors. This is a common model for content-heavy sites.
- Per request. You pay for each request answered. This suits APIs and sites with many small files, where the number of requests matters more than their size.
- Regional rates. Delivering to some parts of the world costs more than others, because bandwidth is pricier there.
- Flat rate or subscription. A fixed fee covers an allowance, with extra usage billed on top or capped.
- Free tiers. A small allowance at no cost, useful for testing and small sites, with limits on volume or features.
What Makes the Bill Grow
Cost depends mainly on three things: how much data leaves the network, how many requests are made, and where visitors are. A site with large images or video pays more per visitor than a text-only site. A site with many tiny requests, such as an app that loads hundreds of small files, may pay more on request counts.
Caching affects cost too. A high cache hit ratio means fewer requests reach the origin, which lowers the origin's own bandwidth costs. It does not reduce the CDN's delivery charges, because visitors still receive every byte. Extra features such as image processing, security filtering or detailed logs are often priced separately, so they can add a surprising amount. Whether the cost is justified for a given site is covered in is a CDN worth it.
Example: Same Visitors, Different Bills
Two sites each receive the same number of visitors in a month. The first is a written blog, with pages that are mostly text and a few small images. The second is a portfolio of high-resolution video. Their request counts may be similar, but the portfolio transfers far more data, so under a per-gigabyte model its bill will be much higher.
This is why a careful estimate should cover both the request volume and the size of the files served before comparing plans.
Frequently asked questions
Is a CDN free?
Some are, within limits. Many providers offer a free tier with a monthly allowance and restricted features. Sites that exceed the allowance, need advanced features or serve high volumes usually move to a paid plan. Check the current terms of any provider, because free allowances change.
Why do CDN bills differ so much between providers?
Each provider sets its own rates, regional prices and included allowances. Some bundle services that others charge for separately, so two bills for the same traffic can differ greatly. Compare providers using the same usage profile, including requests, transfer and regions, rather than headline rates. Running two providers at once multiplies these costs, as discussed in multi-CDN.