Vary for Images: Serve the Correct Images to the Correct Browsers

What this post added

This post introduces support for the HTTP `Vary: Accept` header specifically for images. It explains how this header enables Cloudflare's cache to serve different image variants (like WebP or AVIF) based on the browser's `Accept` header, preventing the delivery of unsupported image formats and improving performance by leveraging edge caching for these variants. It also details how to configure this feature via the Cloudflare API and discusses related image optimization tools.