What is an Image CDN?

A content delivery network (CDN) is a global network of servers that optimizes web performance by using the node closest to the user for faster delivery of assets. An Image CDN adds device detection and image optimization prior to delivering images from the CDN. An Image CDN decreases image payload, delivers images tailored exactly to each requesting device, and instantly sends images from the edge of the network. The result is faster page loading that drives higher SEO ranking and better user experience.

Step 1: Device Detection

Device detection is an image CDN’s first and most critical step. It detects the requesting device model and all capabilities that impact image size and quality. This includes operating system version, screen pixel density, screen resolution, and support for next-generation image and video file formats.

Step 2: Image Optimization

An image CDN will leverage the device detection parameters to automatically resize, compress and convert large original images into optimized images with next-generation file formats. These optimized images are tailored specifically to a requesting device. Frequently, an image CDN will reduce the image payload by up to 80%

Step 3: Global Content Delivery Network (CDN)

An image CDN has edge servers strategically positioned around the globe. These edge servers detect devices and cache-optimized images. When a similar device requests an image again, the image CDN responds immediately with the already-cached optimized image. By pushing optimized images closer to requesting customers with logic to deliver immediately from the cache, an image CDN can often provide a 50% faster web page download time.