Serve images from custom paths

You can use Transform Rules to rewrite URLs for every image that you transform through Image Resizing.

This page covers examples for the following scenarios:

• Serve images from custom paths
• Modify existing URLs to be compatible with Image Resizing
• Pass every image requested on your zone through Image Resizing

To create a rule, log in to the Cloudflare dashboard and select your account and website. Then, select Rules > Transform Rules.

​​ Before you start

Every rule runs before and after the Image Resizing request.

If the path for the request matches the path where the original images are stored on your server, this may cause the request to fetch the original image to loop.

To direct the request to the origin server, you can check for the string image-resizing in the Via header:

...and (not (any(http.request.headers["via"][*] contains "image-resizing")))

​​ Serve images from custom paths

By default, requests to transform images through Image Resizing are served from the /cdn-cgi/image/ path. You can use Transform Rules to rewrite URLs.

​​ Basic version

Free and Pro plans only support string matching rules that do not require regular expressions.

This example lets you rewrite a request from example.com/images to example.com/cdn-cgi/image/:

Text in Expression Editor
(starts_with(http.request.uri.path, "/images")) and (not (any(http.request.headers["via"][*] contains "image-resizing")))

Text in Path > Rewrite to... > Dynamic
concat("/cdn-cgi/images", substring(http.request.uri.path, 7))

​​ Advanced version

There is an advanced version of Transform Rules supporting regular expressions.

This example lets you rewrite a request from example.com/images to example.com/cdn-cgi/image/:

Text in Expression Editor
(http.request.uri.path matches "^/images/.*$") and (not (any(http.request.headers["via"][*] contains "image-resizing")))

Text in Path > Rewrite to... > Dynamic
regex_replace(http.request.uri.path, "^/images/", "/cdn-cgi/image/")

​​ Modify existing URLS to be compatible with Image Resizing

This example lets you rewrite your URL parameters to be compatible with Image Resizing:

Text in Expression Editor
(http.request.uri matches "^/(.*)\\?width=([0-9]+)&height=([0-9]+)$")

Text in Path > Rewrite to... > Dynamic
regex_replace(
  http.request.uri.path,
  "^/(.*)\\?width=([0-9]+)&height=([0-9]+)$",
  "/cdn-cgi/image/width=${2},height=${3}/${1}"
)

Leave the Query > Rewrite to… > Static field empty.

​​ Pass every image requested on your zone through Image Resizing

This example lets you pass every image that is requested on your zone through Image Resizing with the format=auto option:

Text in Expression Editor
(http.request.uri.path.extension matches "(jpg)|(jpeg)|(png)|(gif)") and (not (any(http.request.headers["via"][*] contains "image-resizing")))

Text in Path > Rewrite to... > Dynamic
regex_replace(http.request.uri.path, "/(.*)", "/cdn-cgi/image/format=auto/${1}")