Cloudflare's Image Resizing is a great alternative to resizing images in your Rails app. You get to resize images on-the-fly without adding any load to your server.
This gem make it easy to pass cloudflare's resizing settings via a pair of helpers:
Helper to use resized_image and also build an image_tag.
Automatically adds a srcset with the same image in 2x and 3x (unless you provide a srcset.) See: https://developers.cloudflare.com/images/image-resizing/responsive-images/#srcset-for-high-dpi-displays
Example usage:
<%= resized_image_tag(@user.avatar, {width: 100, fit: "crop"}, alt: "Cropped avatar" %>Helper return a URL with the applied resizing settings
Example usage:
<%= image_tag resized_image(@user.avatar, width: 100, fit: "crop"), alt: "Cropped avatar" %>If you pass preload: true with the resize options, then add <%= yield(:cloudflare_image_resizing_preload) %> to your <head>, you will get <link rel="preload"> for the images.
You can use the helpers outside of a controller or view, simply include CloudflareImageResizing::Helper where you need it.
Not all formats are resizable. See Cloudflare's docs on format limitations
tl;dr: these helpers only try to resize image/jpeg, image/gif, image/png, and image/webp. Other formats are passed through without resizing.
- You are using Cloudflare and have Image Resizing enabled.
- You're using Rails
- You have images either in ActiveStorage or referenced by a URL.
Add this line to your application's Gemfile:
gem "cloudflare_image_resizing"You can use an initializer to configure the enabled flag (defaults to true for non-local environments (production), checking Rails.env.local?.)
Rails.application.config.cloudflare_image_resizing.enabled = falseNote: Image resizing doesn't work from localhost, as Cloudflare needs to be able to proxy the request. For that reason, we only enable resizing in production. When disabled, the helpers just return the image path without resize options.
Open a PR. Be kind. Make the world a better place.
We built this for our own use cases and many have not run into yours. Let us know of omissions, but be prepared to do the work yourself.
The gem is available as open source under the terms of the MIT License.