See heroku-deflater gem.

Author: winston

Gemfile

@@ -58,4 +58,5 @@ gem 'font-awesome-sass'
 
 group :staging, :production do
   gem 'rails_12factor'
+  gem 'heroku-deflater'
 end

Gemfile.lock

@@ -61,6 +61,8 @@ GEM
       sass (>= 3.2)
     globalid (0.3.6)
       activesupport (>= 4.1.0)
+    heroku-deflater (0.5.3)
+      rack (>= 1.4.5)
     i18n (0.7.0)
     jbuilder (2.3.2)
       activesupport (>= 3.0.0, < 5)
@@ -167,6 +169,7 @@ DEPENDENCIES
   byebug
   coffee-rails (~> 4.1.0)
   font-awesome-sass
+  heroku-deflater
   jbuilder (~> 2.0)
   jquery-rails
   pg