Embeds assets from Rails directly into HTML
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.



WithEmbeddedAssets is a gem that allows you to easily embed CSS, JavaScript and images into your Rails generated HTML. It uses the asset pipeline to include compiled assets directly into templates.

The syntax is easy to use, and it is absolutely not intrusive, using Ruby blocks to set the functionality on and off. However, you can also set it to be always on, if desired.

The gem code is thread-safe, and using it in one thread will not affect the behaviour in others.


Add this line to your Rails application's Gemfile:

gem 'with_embedded_assets'

And then execute:

$ bundle


The usage is very simple. Suppose you have a render method in a controller action:

def index
  # action stuff goes here...
  render "template"

If you want it to render the assets of the template embedded in it just put the render method inside a block and give it to the with_embedded_assets method:

def index
  # action stuff goes here...
  with_embedded_assets do
    render "template"

You can also do this inside an ERB template:

<% with_embedded_assets do %>
  <%= render :partial => "partial" %>
<% end %>

Or inside a HAML template:

- with_embedded_assets do
  = render :partial => "partial"

To set it as always on just put this line somewhere on your code, like in a config/initializer file:

WithEmbeddedAssets.enabled = true

To turn it off, just set it to false:

WithEmbeddedAssets.enabled = false

And you can always check it if it is on with this:

WithEmbeddedAssets.enabled? # returns true or false

Also, using the with_embedded_assets temporarily set assets embedding on, but returns to the original state after execution, even if there was an exception during the execution of the block.


Keep in mind that Internet Explorer up to version 7 has no support to embedded images, and verion 8 has a very restricting image size limit (must be smaller than 32 KiB).

Using embedded images increases in size due to the Base64 encoding. This can be mitigated by HTTP compression, but it is still worth noting.


  • Add support for embedding fonts;
  • Add support for embedding images with the image_tag view helpers;
  • Add embedded assets minified to reduce file size in production environment;

Running tests

This gem uses the standard Ruby test suite for the automated tests. First install all the gem dependencies:

$ bundle install

After that you can run all the tests:

$ bundle exec rake test


This gem uses portions of code from the embed-assets-rails gem. You can check the original gem project here:



  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request