Cloudflare Docs
Images
Visit Cloudflare Image Optimization on GitHub
Set theme to dark (⇧+D)

Cloudflare Polish

Cloudflare Polish is a one-click image optimization product that automatically optimizes images in your site. Polish strips metadata from images and reduces image size through lossy or lossless compression to accelerate the speed of image downloads.

When an image is fetched from your origin, our systems automatically optimize it in Cloudflare’s cache. Subsequent requests for the same image will get the smaller, faster, optimized version of the image, improving the speed of your website.

Example of Polish compression’s quality.

Polish compression options

With Lossless and Lossy modes, Cloudflare attempts to strip as much metadata as possible. However, Cloudflare cannot guarantee stripping all metadata because other factors, such as caching status, might affect which metadata is finally sent in the response.

Lossless

Lossless attempts to strip most metadata, like EXIF data, but does not change the image detail. Effectively, when uncompressed, a lossless image is identical to the original. On average, Lossless compression reduces file size by 21 percent.

Lossy

Lossy attempts to strip most metadata and compresses images by approximately 15 percent. When uncompressed, some of the redundant information from the original image is lost. On average, using Lossy mode reduces file size by 48 percent. Lossy has the same effect as Lossless when applied to PNG.

WebP

WebP is a modern image format providing superior lossless and lossy compression for images. WebP lossless images are approximately 26 percent smaller than PNGs, while lossy images are 25 to 34 percent smaller than JPEGs. WebP is supported in all browsers except for Internet Explorer and KaiOS. Safari supports WebP from iOS 14 and MacOS 11 (Big Sur). You can learn more in our blog post.

Polish creates and caches a WebP version of the image and delivers it to the browser if the Accept header from the browser includes WebP, and the compressed image is significantly smaller than the lossy or lossless compression:

Accept: image/avif,image/webp,image/*,*/*;q=0.8

Polish interaction with Image optimization

Polish will not be applied to URLs using Image Resizing. Resized images already have lossy compression applied where possible, so they do not need the optimizations provided by Polish. Use format=auto option to allow use of WebP and AVIF formats.