diff --git a/app/logical/sources/site.rb b/app/logical/sources/site.rb
index 313db6cc6..6e785b8f2 100644
--- a/app/logical/sources/site.rb
+++ b/app/logical/sources/site.rb
@@ -20,16 +20,18 @@ module Sources
       end
     end
 
+    def normalized_for_artist_finder?
+      available? && strategy.normalized_for_artist_finder?
+    end
+
     def normalize_for_artist_finder!
-      if available?
-        begin
-          return strategy.normalize_for_artist_finder!
-        rescue Sources::Error
-          return url
-        end
+      if available? && strategy.normalizable_for_artist_finder?
+        strategy.normalize_for_artist_finder!
       else
-        return url
+        url
       end
+    rescue
+      url
     end
 
     def translated_tags
diff --git a/app/logical/sources/strategies/base.rb b/app/logical/sources/strategies/base.rb
index 6fad07ac5..fe1978ea2 100644
--- a/app/logical/sources/strategies/base.rb
+++ b/app/logical/sources/strategies/base.rb
@@ -18,6 +18,27 @@ module Sources
         raise NotImplementedError
       end
 
+      # Subclasses should return true only if the URL is in its final normalized form.
+      #
+      # Sources::Site.new("http://img.pixiv.net/img/evazion").normalized_for_artist_finder?
+      # => true
+      # Sources::Site.new("http://i2.pixiv.net/img18/img/evazion/14901720_m.png").normalized_for_artist_finder?
+      # => false
+      def normalized_for_artist_finder?
+        false
+      end
+
+      # Subclasses should return true only if the URL is a valid URL that could
+      # be converted into normalized form.
+      #
+      # Sources::Site.new("http://www.pixiv.net/member_illust.php?mode=medium&illust_id=18557054").normalizable_for_artist_finder?
+      # => true
+      # Sources::Site.new("http://dic.pixiv.net/a/THUNDERproject").normalizable_for_artist_finder?
+      # => false
+      def normalizable_for_artist_finder?
+        false
+      end
+
       def normalize_for_artist_finder!
         url
       end
diff --git a/app/logical/sources/strategies/pixiv.rb b/app/logical/sources/strategies/pixiv.rb
index 0c852e44d..18f187199 100644
--- a/app/logical/sources/strategies/pixiv.rb
+++ b/app/logical/sources/strategies/pixiv.rb
@@ -3,12 +3,22 @@
 require 'csv'
 
 module Sources
+  class Error < StandardError ; end
+
   module Strategies
     class Pixiv < Base
       attr_reader :zip_url, :ugoira_frame_data, :ugoira_content_type
       
+      MONIKER   = '(?:[a-zA-Z0-9_-]+)'
+      TIMESTAMP = '(?:[0-9]{4}/[0-9]{2}/[0-9]{2}/[0-9]{2}/[0-9]{2}/[0-9]{2})'
+      EXT = "(?:jpg|jpeg|png|gif)"
+
+      WEB = "^(?:https?://)?www\\.pixiv\\.net"
+      I12 = "^(?:https?://)?i[12]\\.pixiv\\.net"
+      IMG = "^(?:https?://)?img[0-9]*\\.pixiv\\.net"
+
       def self.url_match?(url)
-        url =~ /^https?:\/\/(?:\w+\.)?pixiv\.net/
+        url =~ /#{WEB}|#{IMG}|#{I12}/i
       end
 
       def referer_url(template)
@@ -27,18 +37,25 @@ module Sources
         @pixiv_moniker
       end
 
+      def normalized_for_artist_finder?
+        url =~ %r!http://img\.pixiv\.net/img/#{MONIKER}/?$!i
+      end
+
+      def normalizable_for_artist_finder?
+        has_moniker? || sample_image? || full_image? || work_page?
+      end
+
       def normalize_for_artist_finder!
-        # http://i2.pixiv.net/img04/img/syounen_no_uta/46170939_m.jpg
-        if url =~ %r!/img/([^/]+)/\d+(?:_\w+)?\.(?:jpg|jpeg|png|gif)!i
-          username = $1
+        if has_moniker?
+          moniker = get_moniker_from_url
         else
           illust_id = illust_id_from_url(url)
           get_metadata_from_spapi!(illust_id) do |metadata|
-            username = metadata[24]
+            moniker = metadata[24]
           end
         end
 
-        "http://img.pixiv.net/img/#{username}"
+        "http://img.pixiv.net/img/#{moniker}/"
       end
 
       def get
@@ -77,7 +94,7 @@ module Sources
       # http://i1.pixiv.net/c/600x600/img-master/img/2014/10/02/13/51/23/46304396_p1_master1200.jpg
       # => http://i1.pixiv.net/img-original/img/2014/10/02/13/51/23/46304396_p1.png
       def rewrite_new_medium_images(thumbnail_url)
-        if thumbnail_url =~ %r!/c/\d+x\d+/img-master/img/.*/\d+_p\d+_\w+\.jpg!i
+        if thumbnail_url =~ %r!/c/\d+x\d+/img-master/img/#{TIMESTAMP}/\d+_p\d+_\w+\.jpg!i
           thumbnail_url = thumbnail_url.sub(%r!/c/\d+x\d+/img-master/!i, '/img-original/')
           # => http://i1.pixiv.net/img-original/img/2014/10/02/13/51/23/46304396_p1_master1200.jpg
 
@@ -117,7 +134,7 @@ module Sources
       # => http://i2.pixiv.net/img18/img/evazion/14901720.png
       #
       def rewrite_old_small_and_medium_images(thumbnail_url, is_manga)
-        if thumbnail_url =~ %r!/img/[^/]+/\d+_[ms]\.(?:jpg|jpeg|png|gif)!i
+        if thumbnail_url =~ %r!/img/#{MONIKER}/\d+_[ms]\.#{EXT}!i
           if is_manga.nil?
             illust_id = illust_id_from_url(@url)
             get_metadata_from_spapi!(illust_id) do |metadata|
@@ -141,7 +158,7 @@ module Sources
         # http://i2.pixiv.net/img04/img/syounen_no_uta/46170939_p0.jpg
         # http://i1.pixiv.net/c/600x600/img-master/img/2014/09/24/23/25/08/46168376_p0_master1200.jpg
         # http://i1.pixiv.net/img-original/img/2014/09/25/23/09/29/46183440_p0.jpg
-        if url =~ %r!/\d+_p(\d+)(?:_\w+)?\.(?:jpg|jpeg|png|gif|zip)!i
+        if url =~ %r!/\d+_p(\d+)(?:_\w+)?\.#{EXT}!i
           $1
 
         # http://www.pixiv.net/member_illust.php?mode=manga_big&illust_id=46170939&page=0
@@ -178,6 +195,23 @@ module Sources
         end
       end
 
+      def get_moniker_from_url
+        case url
+        when %r!#{IMG}/img/(#{MONIKER})!i
+          $1
+        when %r!#{I12}/img[0-9]+/img/(#{MONIKER})!i
+          $1
+        when %r!#{WEB}/stacc/(#{MONIKER})/?$!i
+          $1
+        else
+          false
+        end
+      end
+
+      def has_moniker?
+        get_moniker_from_url != false
+      end
+
       def get_image_url_from_page(page, is_manga)
         elements = page.search("div.works_display a img").find_all do |node|
           node["src"] !~ /source\.pixiv\.net/
@@ -258,10 +292,39 @@ module Sources
         agent.get(spapi_url) do |response|
           metadata = CSV.parse(response.content.force_encoding("UTF-8")).first
 
-          if metadata.nil?
-            raise Sources::Error.new("Couldn't get Pixiv API metadata from #{spapi_url}.")
-          else
-            yield metadata
+          validate_spapi_metadata!(metadata)
+          yield metadata
+        end
+      end
+
+      def validate_spapi_metadata!(metadata)
+        if metadata.nil?
+          raise Sources::Error.new("Pixiv API returned empty response.")
+        elsif metadata.size != 31
+          raise Sources::Error.new("Pixiv API returned unexpected number of fields.")
+        end
+
+        illust_id  = metadata[0]
+        file_ext   = metadata[2]
+        page_count = metadata[19]
+        moniker    = metadata[24]
+        mobile_profile_image = metadata[30]
+
+        if file_ext !~ /#{EXT}/i
+          raise Sources::Error.new("Pixiv API returned unexpected file extension '#{file_ext}' for pixiv ##{illust_id}.")
+        elsif moniker !~ /#{MONIKER}/i
+          raise Sources::Error.new("Pixiv API returned invalid artist moniker '#{moniker}' for pixiv ##{illust_id}.")
+        elsif page_count.to_s !~ /[0-9]*/i
+          raise Sources::Error.new("Pixiv API returned invalid page count '#{page_count}' for pixiv ##{illust_id}.")
+        end
+
+        if mobile_profile_image
+          # http://i1.pixiv.net/img01/profile/ccz67420/mobile/5042957_80.jpg
+          profile_regex  = %r!i[12]\.pixiv\.net/img\d+/profile/#{MONIKER}/mobile/\d+_\d+\.jpg!i
+          mobile_moniker = mobile_profile_image.match(profile_regex)[1]
+
+          if mobile_moniker != moniker
+            raise Sources::Error.new("Pixiv API returned inconsistent artist moniker '#{moniker}' for pixiv ##{illust_id}.")
           end
         end
       end
@@ -300,6 +363,73 @@ module Sources
           raise Sources::Error.new("Couldn't get illust ID from URL: #{url}")
         end
       end
+
+      def work_page?
+        return true if url =~ %r!#{WEB}/member_illust\.php\?mode=(?:medium|big|manga|manga_big)&illust_id=\d+!i
+        return true if url =~ %r!#{WEB}/i/\d+$!i
+        return false
+      end
+
+      def full_image?
+        # http://img18.pixiv.net/img/evazion/14901720.png?1234
+        return true if url =~ %r!#{IMG}/img/#{MONIKER}/\d+(?:_big_p\d+)?\.#{EXT}!i
+
+        # http://i2.pixiv.net/img18/img/evazion/14901720.png
+        # http://i1.pixiv.net/img07/img/pasirism/18557054_big_p1.png
+        return true if url =~ %r!#{I12}/img\d+/img/#{MONIKER}/\d+(?:_big_p\d+)?\.#{EXT}!i
+
+        # http://i1.pixiv.net/img-original/img/2014/10/02/13/51/23/46304396_p0.png
+        return true if url =~ %r!#{I12}/img-original/img/#{TIMESTAMP}/\d+_p\d+\.#{EXT}$!i
+
+        # http://i1.pixiv.net/img-zip-ugoira/img/2014/10/03/17/29/16/46323924_ugoira1920x1080.zip
+        return true if url =~ %r!#{I12}/img-zip-ugoira/img/#{TIMESTAMP}/\d+_ugoira\d+x\d+\.zip$!i
+
+        return false
+      end
+
+      def sample_image?
+        # http://img18.pixiv.net/img/evazion/14901720_m.png
+        return true if url =~ %r!#{IMG}/img/#{MONIKER}/\d+_(?:[sm]|p\d+)\.#{EXT}!i
+
+        # http://i2.pixiv.net/img18/img/evazion/14901720_m.png
+        # http://i1.pixiv.net/img07/img/pasirism/18557054_p1.png
+        return true if url =~ %r!#{I12}/img\d+/img/#{MONIKER}/\d+_(?:[sm]|p\d+)\.#{EXT}!i
+
+        # http://i1.pixiv.net/c/600x600/img-master/img/2014/10/02/13/51/23/46304396_p0_master1200.jpg
+        # http://i2.pixiv.net/c/64x64/img-master/img/2014/10/09/12/59/50/46441917_square1200.jpg
+        return true if url =~ %r!#{I12}/c/\d+x\d+/img-master/img/#{TIMESTAMP}/\d+_\w+\.#{EXT}$!i
+
+        # http://i1.pixiv.net/img-inf/img/2011/05/01/23/28/04/18557054_s.png
+        # http://i2.pixiv.net/img-inf/img/2010/11/30/08/54/06/14901765_64x64.jpg
+        return true if url =~ %r!#{I12}/img-inf/img/#{TIMESTAMP}/\d+_\w+\.#{EXT}!i
+
+        return false
+      end
+
+      def agent
+        @agent ||= begin
+          mech = Mechanize.new
+
+          phpsessid = Cache.get("pixiv-phpsessid")
+          if phpsessid
+            cookie = Mechanize::Cookie.new("PHPSESSID", phpsessid)
+            cookie.domain = ".pixiv.net"
+            cookie.path = "/"
+            mech.cookie_jar.add(cookie)
+          else
+            mech.get("http://www.pixiv.net") do |page|
+              page.form_with(:action => "/login.php") do |form|
+                form['pixiv_id'] = Danbooru.config.pixiv_login
+                form['pass'] = Danbooru.config.pixiv_password
+              end.click_button
+            end
+            phpsessid = mech.cookie_jar.cookies.select{|c| c.name == "PHPSESSID"}.first
+            Cache.put("pixiv-phpsessid", phpsessid.value, 1.month) if phpsessid
+          end
+
+          mech
+        end
+      end
     end
   end
 end
diff --git a/app/models/artist.rb b/app/models/artist.rb
index d28cd0448..154bb075d 100644
--- a/app/models/artist.rb
+++ b/app/models/artist.rb
@@ -22,10 +22,11 @@ class Artist < ActiveRecord::Base
 
     module ClassMethods
       def find_all_by_url(url)
-        url = Sources::Site.new(url).normalize_for_artist_finder!
         url = ArtistUrl.normalize(url)
         artists = []
 
+        # return [] unless Sources::Site.new(url).normalized_for_artist_finder?
+
         while artists.empty? && url.size > 10
           u = url.sub(/\/+$/, "") + "/"
           u = u.to_escaped_for_sql_like.gsub(/\*/, '%') + '%'
diff --git a/app/models/artist_url.rb b/app/models/artist_url.rb
index 361007c79..575deb933 100644
--- a/app/models/artist_url.rb
+++ b/app/models/artist_url.rb
@@ -1,4 +1,5 @@
 class ArtistUrl < ActiveRecord::Base
+  before_save :initialize_normalized_url, on: [ :create ]
   before_save :normalize
   validates_presence_of :url
   belongs_to :artist
@@ -12,8 +13,7 @@ class ArtistUrl < ActiveRecord::Base
       url = url.gsub(/^http:\/\/blog\d+\.fc2/, "http://blog.fc2")
       url = url.gsub(/^http:\/\/blog-imgs-\d+\.fc2/, "http://blog.fc2")
       url = url.gsub(/^http:\/\/blog-imgs-\d+-\w+\.fc2/, "http://blog.fc2")
-      url = url.gsub(/^http:\/\/img\d+\.pixiv\.net/, "http://img.pixiv.net")
-      url = url.gsub(/^http:\/\/i\d+\.pixiv\.net\/img\d+/, "http://img.pixiv.net")
+      url = Sources::Site.new(url).normalize_for_artist_finder!
       url = url.gsub(/\/+\Z/, "")
       url + "/"
     end
@@ -33,7 +33,13 @@ class ArtistUrl < ActiveRecord::Base
   end
 
   def normalize
-    self.normalized_url = self.class.normalize(url)
+    if !Sources::Site.new(normalized_url).normalized_for_artist_finder?
+      self.normalized_url = self.class.normalize(url)
+    end
+  end
+
+  def initialize_normalized_url
+    self.normalized_url = url
   end
 
   def to_s
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 60dd2dd6d..0e939a4f9 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -105,4 +105,11 @@ VCR.configure do |c|
   c.cassette_library_dir = "test/fixtures/vcr_cassettes"
   c.hook_into :webmock
   # c.allow_http_connections_when_no_cassette = true
+
+  c.default_cassette_options = {
+    match_requests_on: [
+      :method,
+      VCR.request_matchers.uri_without_param(:PHPSESSID)
+    ]
+  }
 end