diff --git a/app/controllers/moderator/tags_controller.rb b/app/controllers/moderator/tags_controller.rb
new file mode 100644
index 000000000..d579d7651
--- /dev/null
+++ b/app/controllers/moderator/tags_controller.rb
@@ -0,0 +1,14 @@
+module Moderator
+  class TagsController < ApplicationController
+    before_filter :moderator_only
+    
+    def edit
+    end
+    
+    def update
+      tag_batch_change = TagBatchChange.new(params[:tag][:predicate], params[:tag][:consequent])
+      tag_batch_change.execute
+      redirect_to edit_moderator_tag_path, :notice => "Posts updated"
+    end
+  end
+end
diff --git a/app/logical/moderator/tag_batch_change.rb b/app/logical/moderator/tag_batch_change.rb
new file mode 100644
index 000000000..835612239
--- /dev/null
+++ b/app/logical/moderator/tag_batch_change.rb
@@ -0,0 +1,24 @@
+module Moderator
+  class TagBatchChange
+    class Error < Exception ; end
+    
+    attr_reader :predicate, :consequent
+    
+    def initialize(predicate, consequent)
+      @predicate = predicate
+      @consequent = consequent
+    end
+    
+    def execute
+      raise Error.new("Predicate is missing") if predicate.blank?
+      
+      normalized_predicate = TagAlias.to_aliased(::Tag.scan_tags(predicate))
+      normalized_consequent = TagAlias.to_aliased(::Tag.scan_tags(consequent))
+
+      ::Post.tag_match(predicate).each do |post|
+        tags = (post.tag_array - normalized_predicate + normalized_consequent).join(" ")
+        post.update_attributes(:tag_string => tags)
+      end
+    end
+  end
+end
diff --git a/app/models/tag.rb b/app/models/tag.rb
index ee6d65cf6..2df386603 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -106,21 +106,7 @@ class Tag < ActiveRecord::Base
       m.extend(ClassMethods)
     end
   end
-  
-  module UpdateMethods
-    def mass_edit(start_tags, result_tags, updater_id, updater_ip_addr)
-      updater = User.find(updater_id)
-      Post.tag_match(start_tags).each do |p|
-        start = TagAlias.to_aliased(scan_tags(start_tags))
-        result = TagAlias.to_aliased(scan_tags(result_tags))
-        tags = (p.tag_array - start + result).join(" ")
-        CurrentUser.scoped(updater, updater_ip_addr) do
-          p.update_attributes(:tag_string => tags)
-        end
-      end    
-    end
-  end
-  
+
   module ParseMethods
     def normalize(query)
       query.to_s.downcase.strip
@@ -367,7 +353,6 @@ class Tag < ActiveRecord::Base
   include CategoryMethods
   extend StatisticsMethods
   include NameMethods
-  extend UpdateMethods
   extend ParseMethods
   extend SuggestionMethods
 end
diff --git a/app/views/moderator/tags/edit.html.erb b/app/views/moderator/tags/edit.html.erb
new file mode 100644
index 000000000..0b56da32a
--- /dev/null
+++ b/app/views/moderator/tags/edit.html.erb
@@ -0,0 +1,21 @@
+<div id="c-moderator-tags">
+  <div id="a-edit">
+    <h1>Edit Tags</h1>
+    
+    <%= form_tag(moderator_tag_path, :method => :put) do %>
+      <div class="input">
+        <label>Predicate</label>
+        <%= text_field :tag, :predicate %>
+      </div>
+      
+      <div class="input">
+        <label>Consequent</label>
+        <%= text_field :tag, :consequent %>
+      </div>
+      
+      <div class="input">
+        <%= submit_tag %>
+      </div>
+    <% end %>
+  </div>
+</div>
diff --git a/config/routes.rb b/config/routes.rb
index dda1785a8..f7bc45a8a 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -10,7 +10,7 @@ Danbooru::Application.routes.draw do
       end
     end
     resources :invitations, :only => [:new, :create, :index]
-    resource :tag
+    resource :tag, :only => [:edit, :update]
     namespace :post do
       resource :dashboard, :only => [:show]
       resource :approval, :only => [:create]
diff --git a/test/unit/moderator/tag_batch_change_test.rb b/test/unit/moderator/tag_batch_change_test.rb
new file mode 100644
index 000000000..c547b6a45
--- /dev/null
+++ b/test/unit/moderator/tag_batch_change_test.rb
@@ -0,0 +1,33 @@
+require "test_helper"
+
+module Moderator
+  class TagBatchChangeTest < ActiveSupport::TestCase
+    context "a tag batch change" do
+      setup do
+        @user = Factory.create(:moderator_user)
+        CurrentUser.user = @user
+        CurrentUser.ip_addr = "127.0.0.1"
+        @post = Factory.create(:post, :tag_string => "aaa")
+      end
+  
+      teardown do
+        CurrentUser.user = nil
+        CurrentUser.ip_addr = nil
+      end
+
+      should "execute" do
+        tag_batch_change = TagBatchChange.new("aaa", "bbb")
+        tag_batch_change.execute
+        @post.reload
+        assert_equal("bbb", @post.tag_string)
+      end
+      
+      should "raise an error if there is no predicate" do
+        tag_batch_change = TagBatchChange.new("", "bbb")
+        assert_raises(TagBatchChange::Error) do
+          tag_batch_change.execute
+        end
+      end
+    end
+  end
+end