Ruby/Rails SDK
Last updated: May-17-2023
This page provides an in-depth introduction to the Ruby/Rails SDK.
Overview
Cloudinary's Ruby/Rails SDK provides simple, yet comprehensive image and video upload, transformation, optimization, and delivery capabilities that you can implement using code that integrates seamlessly with your existing Ruby/Rails application.
For details on all new features and fixes from previous versions, see the CHANGELOG.
Quick example: Transformations
Take a look at the following transformation code and the image it delivers:

This relatively simple code performs all of the following on the original front_face.jpg image before delivering it:
- Crop to a 150x150 thumbnail using face-detection gravity to automatically determine the location for the crop
- Round the corners with a 20 pixel radius
- Apply a sepia effect
- Overlay the Cloudinary logo on the southeast corner of the image (with a slight offset). The logo is scaled down to a 50 pixel width, with increased brightness and partial transparency (opacity = 60%)
- Rotate the resulting image (including the overlay) by 10 degrees
- Convert and deliver the image in PNG format (the originally uploaded image was a JPG)
And here's the URL that would be included in the image tag that's automatically generated from the above code:
In a similar way, you can transform a video.
- See all possible transformations in the Transformation URL API reference.
- See more examples of image and video transformations using the
cloudinary_gem
library.
Quick example: File upload
The following Ruby code uploads the dog.mp4
video to the specified sub-folder using the public_id, my_dog
. The video will overwrite the existing my_dog
video if it exists. When the video upload is complete, the specified notification URL will receive details about the uploaded media asset.
Ruby gem features
Cloudinary provides a Ruby gem (open source) that simplifies the integration with your Ruby and Ruby on Rails applications:
- Build URLs for image and video transformations
- Rails view helper tags for embedding and transforming images
- API wrappers: file upload, administration, sprite generation and more
- Server-side file upload + direct unsigned file upload from the browser using the jQuery plugin
- Migration tool
- Active Storage integration
- CarrierWave plugin
- Static image syncing for CDN delivery
- General Ruby integration for non-Rails frameworks such as Sinatra
Installation
Cloudinary's Ruby library is available as an open-source Ruby gem.
To install the Cloudinary Ruby gem, run:
If you use Rails 3.x or later, edit your Gemfile, add the following line and run bundle.
Or in Rails 2.x, edit your environment.rb and add:
Configuration
To use the Cloudinary Ruby/Rails library, you have to configure at least your cloud_name
. Your api_key
and api_secret
are also needed for secure API calls to Cloudinary (e.g., image and video uploads). You can find your product environment configuration credentials in the Dashboard page of the Cloudinary Console.
In addition to the required configuration parameters, you can define a number of optional configuration parameters if relevant.
You can set your configuration parameters:
- Individually, by passing configuration parameters in Cloudinary method calls
- Globally by defining the CLOUDINARY_URL environment variable (required parameters only)
- Globally in a cloudinary.yml file
- Globally in an initializer file
- You can always override the values specified in
cloudinary.yml
or initializer file by passing different values in specific Cloudinary calls. - If you use more than one method of setting configuration options, the order of precedence is:
CLOUDINARY_URL
->cloud_name
->cloudinary.yml
/cloudinary.rb
- For backward compatibility reasons, the default value of the optional
secure
configuration parameter isfalse
. However, for most modern applications, it's recommended to configure thesecure
parameter totrue
to ensure that your transformation URLs are always generated as HTTPS.
Setting the CLOUDINARY_URL environment variable
You can configure the required cloud_name
, api_key
, and api_secret
by defining the CLOUDINARY_URL environment variable. The CLOUDINARY_URL value is available in the Dashboard page of the Cloudinary Console. When using Cloudinary through a PaaS add-on (e.g., Heroku or AppFog), this environment variable is automatically defined in your deployment environment. For example:
Set additional parameters, for example upload_prefix and cname, to the environment variable:
cloudinary.yml method
Configure your Cloudinary credentials and any other optional configuration options (for example, secure:true
) as follows:
cloudinary.yml
file under the config folder of your Rails project. initializer method
Configure your Cloudinary credentials and any other optional configuration options (for example, secure:true
) as follows:
Or alternatively
cloudinary.rb
in the /config/initializers folder of your Rails project. Ruby capitalization and data type guidelines
When using the Ruby/Rails SDK, keep these guidelines in mind:
- Parameter names:
snake_case
. For example: public_id - Classes:
PascalCase
. For example: PictureUploader - Methods:
snake_case
. For example: cl_image_upload_tag - Pass parameter data as:
Hash
Sample projects
For additional useful code samples and to learn how to integrate Cloudinary with your Rails applications, take a look at our Sample Projects.
- Basic Ruby sample: Uploading local and remote images to Cloudinary and generating various transformation URLs.
- Basic Rails sample: Uploading local and remote images in a Rails project while embedding various transformed images in a Rails web view.
- Rails Photo Album: A fully working web application. It uses CarrierWave to manage images of an album model (database). Performs image uploading both from the server side and directly from the browser using a jQuery plugin.
- Get your first Ruby/Rails SDK project up and running in ~5 minutes with the Ruby/Rails SDK quick start.
- Learn more about uploading images and videos.
- See examples of powerful image and video transformations using Ruby code
and see our image transformations and video transformation docs.
- Check out Cloudinary's asset administration capabilities, for example, renaming and deleting assets, adding tags and metadata to assets, and searching for assets.
- Make sure to read about Rails Carrierwave, Attachinary, and ActiveStorage integrations.
- Stay tuned for updates, tips and tutorials in Product Updates and Blog Posts.