Next Gen Images

Update: Since Rails 7.1 and this PR, Rails has a picture HTML tag helper.

This gem provides helpers to simplify the transition to using WebP images in Ruby on Rails. A Carrierwave module with some utility methods is provided.

IMPORTANT: Since this gem adds the ability to convert all your project images to WebP and depends on webp-ffi, you will need to install the WebP converter before. You can check specific instructions for your operating system here

Once you are ready with, install the gem and add to the application's Gemfile by executing:

$ bundle add next_gen_images

Or add it to your application's Gemfile

gem 'next_gen_images'

and then run

bundle install

A rake task called next_gen_images:precompile that precompiles all of your images to WebP is provided. You can enable it so it runs automatically when you do an assets:precompile via an initializer like this:

NextGenImages.configure do |config|
  config.run_on_precompile = true
end

If you want to manually convert your images, you can run:

rake next_gen_images:precompile

Assets will be compiled to public/assets/ or the path that you specifed in Rails.application.config.assets.prefix. The file names of the generated image assets will be in the format:OLD_IMAGE.OLD_EXTENSION.webp

In addition to the next_gen_images:precompile task, there's also a task to convert images in the app/assets/images directory to WebP. It leaves the original images untouched:

rake next_gen_images:convert_app_images

The file names of the generated image assets will be in the format OLD_IMAGE.webp and will be placed in the app/assets/images directory.

If you are using ActiveStorage you will need to first enable the image_processing gem. Usually, uncommenting this from your Gemfile:

gem "image_processing"

Then, you will need to install the VIPS image processing library binaries. Check the VIPS Ruby wrapper gem for installation instructions for your OS.

Finally, in application.rb configure ActiveStorage to use VIPS:

config.active_storage.variant_processor = :vips

You are ready to start using WebP variants in your models like this:

class User < ApplicationRecord
  has_one_attached :avatar do |attachable|
    attachable.variant :small, resize_to_limit: [400, 400]
    attachable.variant :webp, {
      convert: :webp,
      format: :webp,
      saver: { quality: 80 }
    }
    attachable.variant :webp_small, {
      resize_to_limit: [400, 400],
      convert: :webp,
      format: :webp,
      saver: { quality: 80 }
    }
  end
end

A convert_to_webp method that converts images to WebP is provided. You can send any encoding option available to webp-ffi. We also provide a helper method called build_webp_full_filename that allows you to generate the WebP filename from the original filename and version.

Example Uploader class:

class ImageUploader < CarrierWave::Uploader::Base
  include NextGenImages::CarrierwaveHelpers

  version :small do
    process resize_to_fit: [400, 400]
  end

  version :webp do
    process convert_to_webp: [{ quality: 80, method: 5 }]

    def full_filename(file)
      build_webp_full_filename(file, version_name)
    end
  end
end

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/eagerworks/next_gen_images.

The gem is available as open source under the terms of the MIT License.