1. If your Rails version is between > 3.1.0 and < 4, place your fonts in any of the these folders:

    • app/assets/fonts
    • lib/assets/fonts
    • vendor/assets/fonts


    For Rails versions > 4, you must place your fonts in the app/assets/fonts folder.

    Note: To place fonts outside of these designated folders, use the following configuration:

    config.assets.precompile << /\.(?:svg|eot|woff|ttf)\z/

    For Rails versions > 4.2, it is recommended to add this configuration to config/initializers/assets.rb.

    However, you can also add it to either config/application.rb , or to config/production.rb

  2. Declare your font in your CSS file:

    @font-face {
      font-family: 'Icomoon';
      src:url('icomoon.eot');
      src:url('icomoon.eot?#iefix') format('embedded-opentype'),
        url('icomoon.svg#icomoon') format('svg'),
        url('icomoon.woff') format('woff'),
        url('icomoon.ttf') format('truetype');
      font-weight: normal;
      font-style: normal;
    }
    

    Make sure your font is named exactly the same as in the URL portion of the declaration. Capital letters and punctuation marks matter. In this case, the font should have the name icomoon.

  3. If you are using Sass or Less with Rails > 3.1.0 (your CSS file has .scss or .less extension), then change the url(...) in the font declaration to font-url(...).

    Otherwise, your CSS file should have the extension .css.erb, and the font declaration should be url('<%= asset_path(...) %>').

    If you are using Rails > 3.2.1, you can use font_path(...) instead of asset_path(...). This helper does exactly the same thing but it's more clear.

  4. Finally, use your font in your CSS like you declared it in the font-family part. If it was declared capitalized, you can use it like this:

    font-family: 'Icomoon';
    

Now here's a twist:

You should place all fonts in app/assets/fonts/ as they WILL get precompiled in staging and production by default—they will get precompiled when pushed to heroku.

Font files placed in vendor/assets will NOT be precompiled on staging or production by default — they will fail on heroku. Source!

— @plapier, thoughtbot/bourbon

I strongly believe that putting vendor fonts into vendor/assets/fonts makes a lot more sense than putting them into app/assets/fonts. With these 2 lines of extra configuration this has worked well for me (on Rails 4):

app.config.assets.paths << Rails.root.join('vendor', 'assets', 'fonts')  
app.config.assets.precompile << /\.(?:svg|eot|woff|ttf)$/

— @jhilden, thoughtbot/bourbon

I've also tested it on rails 4.0.0. Actually the last one line is enough to safely precompile fonts from vendor folder. Took a couple of hours to figure it out. Hope it helped someone.


If you don't want to keep track of moving your fonts around:

# Adding Webfonts to the Asset Pipeline
config.assets.precompile << Proc.new { |path|
  if path =~ /\.(eot|svg|ttf|woff)\z/
    true
  end
}

You need to use font-url in your @font-face block, not url

@font-face {
font-family: 'Inconsolata';
src:font-url('Inconsolata-Regular.ttf') format('truetype');
font-weight: normal;
font-style: normal;
}

as well as this line in application.rb, as you mentioned (for fonts in app/assets/fonts

config.assets.paths << Rails.root.join("app", "assets", "fonts")