diff --git a/middleman-core/features/relative_assets_helpers_only.feature b/middleman-core/features/relative_assets_helpers_only.feature
new file mode 100644
index 00000000..9d508977
--- /dev/null
+++ b/middleman-core/features/relative_assets_helpers_only.feature
@@ -0,0 +1,123 @@
+Feature: Relative Assets (Helpers Only)
+
+  Scenario: Rendering css with the feature enabled
+    Given a fixture app "relative-assets-app"
+    And a file named "config.rb" with:
+      """
+      activate :relative_assets, helpers_only: true
+      """
+    And a file named "source/stylesheets/relative_assets.css.sass.erb" with:
+      """
+      h1
+        background: url("<%= asset_url('images/blank.gif') %>")
+      h2
+        background: url("<%= asset_url('/images/blank2.gif') %>")
+      """
+    And a file named "source/javascripts/application.js.erb" with:
+      """
+      function foo() {
+        var img = document.createElement('img');
+        img.src = '<%= asset_url("images/100px.jpg") %>';
+        var body = document.getElementsByTagName('body')[0];
+        body.insertBefore(img, body.firstChild);
+      }
+
+      window.onload = foo;
+      """
+    And a file named "source/stylesheets/fonts3.css.erb" with:
+      """
+      @font-face {
+        font-family: 'Roboto2';
+        src: url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.eot") %>);
+        src: url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.eot?#iefix") %>) format('embedded-opentype'),
+            url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.woff") %>) format('woff'),
+            url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.ttf") %>) format('truetype'),
+            url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.svg#robotoregular") %>) format('svg');
+        font-weight: normal;
+        font-style: normal;
+      }
+      """
+    And the Server is running at "relative-assets-app"
+    When I go to "/stylesheets/relative_assets.css"
+    Then I should see 'url("../images/blank.gif'
+    And I should see 'url("../images/blank2.gif'
+    When I go to "/javascripts/application.js"
+    Then I should not see "../"
+    When I go to "/stylesheets/fonts3.css"
+    Then I should see 'url(../fonts/roboto/roboto-regular-webfont.eot'
+    And I should see 'url(../fonts/roboto/roboto-regular-webfont.woff'
+    And I should see 'url(../fonts/roboto/roboto-regular-webfont.ttf'
+    And I should see 'url(../fonts/roboto/roboto-regular-webfont.svg'
+
+  Scenario: Relative css reference with directory indexes
+    Given a fixture app "relative-assets-app"
+    And a file named "config.rb" with:
+      """
+      activate :directory_indexes
+      activate :relative_assets, helpers_only: true
+      """
+    And the Server is running at "relative-assets-app"
+    When I go to "/relative_image/index.html"
+    Then I should see "../stylesheets/relative_assets.css"
+
+  Scenario: Relative assets via image_tag
+    Given a fixture app "relative-assets-app"
+    And a file named "config.rb" with:
+      """
+      activate :relative_assets, helpers_only: true
+      """
+    And a file named "source/sub/image_tag.html.erb" with:
+      """
+      <%= image_tag '/img/blank.gif' %>
+      """
+    And the Server is running at "relative-assets-app"
+    When I go to "/sub/image_tag.html"
+    Then I should see '<img src="../img/blank.gif" />'
+
+  Scenario: Relative assets should not break data URIs in image_tag
+    Given a fixture app "relative-assets-app"
+    And a file named "config.rb" with:
+      """
+      activate :relative_assets, helpers_only: true
+      """
+    And a file named "source/sub/image_tag.html.erb" with:
+      """
+      <%= image_tag "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" %>
+      """
+    And the Server is running at "relative-assets-app"
+    When I go to "/sub/image_tag.html"
+    Then I should see '<img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" />'
+
+  Scenario: URLs are not rewritten for rewrite ignored paths
+    Given a fixture app "relative-assets-app"
+    And a file named "config.rb" with:
+      """
+      activate :relative_assets, rewrite_ignore: [
+        '/stylesheets/fonts3.css',
+      ], helpers_only: true
+      """
+    And a file named "source/stylesheets/relative_assets.css.sass.erb" with:
+      """
+      h1
+        background: url("<%= asset_url('images/blank.gif') %>")
+      h2
+        background: url("<%= asset_url('/images/blank2.gif') %>")
+      """
+    And a file named "source/stylesheets/fonts3.css.erb" with:
+      """
+      @font-face {
+        font-family: 'Roboto2';
+        src: url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.eot") %>);
+        src: url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.eot?#iefix") %>) format('embedded-opentype'),
+            url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.woff") %>) format('woff'),
+            url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.ttf") %>) format('truetype'),
+            url(<%= asset_url("/fonts/roboto/roboto-regular-webfont.svg#robotoregular") %>) format('svg');
+        font-weight: normal;
+        font-style: normal;
+      }
+      """
+    And the Server is running at "relative-assets-app"
+    When I go to "/stylesheets/relative_assets.css"
+    Then I should see 'url("../images/blank.gif'
+    When I go to "/stylesheets/fonts3.css"
+    Then I should see 'url(/fonts/roboto/roboto-regular-webfont.eot'
diff --git a/middleman-core/fixtures/relative-assets-app/source/images/blank2.gif b/middleman-core/fixtures/relative-assets-app/source/images/blank2.gif
new file mode 100644
index 00000000..e69de29b
diff --git a/middleman-core/lib/middleman-core/core_extensions/default_helpers.rb b/middleman-core/lib/middleman-core/core_extensions/default_helpers.rb
index 33b411e1..774522db 100644
--- a/middleman-core/lib/middleman-core/core_extensions/default_helpers.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/default_helpers.rb
@@ -1,4 +1,5 @@
 require 'padrino-helpers'
+require 'middleman-core/contracts'
 
 # Don't fail on invalid locale, that's not what our current
 # users expect.
diff --git a/middleman-core/lib/middleman-core/core_extensions/inline_url_rewriter.rb b/middleman-core/lib/middleman-core/core_extensions/inline_url_rewriter.rb
index 24d541fa..43354e97 100644
--- a/middleman-core/lib/middleman-core/core_extensions/inline_url_rewriter.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/inline_url_rewriter.rb
@@ -11,13 +11,12 @@ module Middleman
 
       expose_to_application rewrite_inline_urls: :add
 
-      IGNORE_DESCRIPTOR = Or[Regexp, RespondTo[:call], String]
       REWRITER_DESCRIPTOR = {
         id: Symbol,
         proc: Or[Proc, Method],
         url_extensions: ArrayOf[String],
         source_extensions: ArrayOf[String],
-        ignore: ArrayOf[IGNORE_DESCRIPTOR],
+        ignore: ArrayOf[::Middleman::Util::IGNORE_DESCRIPTOR],
         after: Maybe[Symbol]
       }.freeze
 
@@ -109,7 +108,7 @@ module Middleman
                 next unless source_exts.include?(::File.extname(path))
 
                 ignore = rewriter.fetch(:ignore)
-                next if ignore.any? { |r| should_ignore?(r, full_asset_path) }
+                next if ignore.any? { |r| ::Middleman::Util.should_ignore?(r, full_asset_path) }
 
                 rewrite_ignore = Array(rewriter[:rewrite_ignore] || [])
                 next if rewrite_ignore.any? { |i| ::Middleman::Util.path_match(i, path) }
@@ -130,24 +129,6 @@ module Middleman
             headers
           ).finish
         end
-
-        Contract IGNORE_DESCRIPTOR, String => Bool
-        def should_ignore?(validator, value)
-          if validator.is_a? Regexp
-            # Treat as Regexp
-            !!(value =~ validator)
-          elsif validator.respond_to? :call
-            # Treat as proc
-            validator.call(value)
-          elsif validator.is_a? String
-            # Treat as glob
-            File.fnmatch(value, validator)
-          else
-            # If some unknown thing, don't ignore
-            false
-          end
-        end
-        memoize :should_ignore?
       end
     end
   end
diff --git a/middleman-core/lib/middleman-core/extensions/relative_assets.rb b/middleman-core/lib/middleman-core/extensions/relative_assets.rb
index 33ac420e..853a7005 100644
--- a/middleman-core/lib/middleman-core/extensions/relative_assets.rb
+++ b/middleman-core/lib/middleman-core/extensions/relative_assets.rb
@@ -2,15 +2,20 @@ require 'addressable/uri'
 
 # Relative Assets extension
 class Middleman::Extensions::RelativeAssets < ::Middleman::Extension
-  option :exts, nil, 'List of extensions that get cache busters strings appended to them.'
+  option :exts, nil, 'List of extensions that get converted to relative paths.'
   option :sources, %w(.css .htm .html .xhtml), 'List of extensions that are searched for relative assets.'
-  option :ignore, [], 'Regexes of filenames to skip adding query strings to'
-  option :rewrite_ignore, [], 'Regexes of filenames to skip processing for path rewrites'
+  option :ignore, [], 'Regexes of filenames to skip converting to relative paths.'
+  option :rewrite_ignore, [], 'Regexes of filenames to skip processing for path rewrites.'
+  option :helpers_only, false, 'Allow only Ruby helpers to change paths.'
 
   def initialize(app, options_hash={}, &block)
     super
 
-    app.rewrite_inline_urls id: :asset_hash,
+    if options[:helpers_only]
+      return
+    end
+
+    app.rewrite_inline_urls id: :relative_assets,
                             url_extensions: options.exts || app.config[:asset_extensions],
                             source_extensions: options.sources,
                             ignore: options.ignore,
@@ -18,16 +23,37 @@ class Middleman::Extensions::RelativeAssets < ::Middleman::Extension
                             proc: method(:rewrite_url)
   end
 
-  helpers do
-    # asset_url override for relative assets
-    # @param [String] path
-    # @param [String] prefix
-    # @param [Hash] options Additional options.
-    # @return [String]
-    def asset_url(path, prefix='', options={})
-      options[:relative] = true unless options.key?(:relative)
+  def mark_as_relative(file_path, opts, current_resource)
+    result = opts.dup
 
-      super(path, prefix, options)
+    valid_exts = options.sources
+
+    return result unless current_resource
+    return result unless valid_exts.include?(current_resource.ext)
+
+    rewrite_ignores = Array(options.rewrite_ignore || [])
+
+    path = current_resource.destination_path
+    return result if rewrite_ignores.any? do |i|
+      ::Middleman::Util.path_match(i, path) || ::Middleman::Util.path_match(i, "/#{path}")
+    end
+
+    return result if Array(options.ignore || []).any? do |r|
+      ::Middleman::Util.should_ignore?(r, file_path)
+    end
+
+    result[:relative] = true unless result.key?(:relative)
+
+    result
+  end
+
+  helpers do
+    def asset_url(path, prefix='', options={})
+      super(path, prefix, app.extensions[:relative_assets].mark_as_relative(super, options, current_resource))
+    end
+
+    def asset_path(kind, source, options={})
+      super(kind, source,  app.extensions[:relative_assets].mark_as_relative(super, options, current_resource))
     end
   end
 
diff --git a/middleman-core/lib/middleman-core/util/paths.rb b/middleman-core/lib/middleman-core/util/paths.rb
index fa25e818..26f29442 100644
--- a/middleman-core/lib/middleman-core/util/paths.rb
+++ b/middleman-core/lib/middleman-core/util/paths.rb
@@ -45,6 +45,25 @@ module Middleman
     end
     memoize :strip_leading_slash
 
+    IGNORE_DESCRIPTOR = Or[Regexp, RespondTo[:call], String]
+    Contract IGNORE_DESCRIPTOR, String => Bool
+    def should_ignore?(validator, value)
+      if validator.is_a? Regexp
+        # Treat as Regexp
+        !!(value =~ validator)
+      elsif validator.respond_to? :call
+        # Treat as proc
+        validator.call(value)
+      elsif validator.is_a? String
+        # Treat as glob
+        File.fnmatch(value, validator)
+      else
+        # If some unknown thing, don't ignore
+        false
+      end
+    end
+    memoize :should_ignore?
+
     # Get the path of a file of a given type
     #
     # @param [Middleman::Application] app The app.