An image CDN is a network of globally distributed servers that transforms, optimizes, and caches your images, then delivers them from the nearest point to each visitor.
Unlike a classic CDN that simply delivers files, an image CDN acts on content: it resizes, converts to the lightest format (WebP, AVIF), and crops on demand, usually driven by URL parameters. The first request produces the variant, the following ones are served from the cache, as close to the visitor as possible.
Key points
On-demand transformation
Size, format, and crop are calculated on the fly from the URL, no pre-generated files.
Distributed cache
Each variant is cached and served from the closest region, for minimal latency.
Performance impact
Lighter and closer images improve LCP, SEO, and your bandwidth bill.
