diff --git a/src/common/globalbroadcaster.cc b/src/common/globalbroadcaster.cc
index e8b1b885..8a4ddb4e 100644
--- a/src/common/globalbroadcaster.cc
+++ b/src/common/globalbroadcaster.cc
@@ -8,7 +8,7 @@ GlobalBroadcaster::GlobalBroadcaster( QObject * parent ):
 {
   QStringList whiteUrlHosts = { "ajax.googleapis.com" };
 
-  for ( auto host : whiteUrlHosts ) {
+  for ( const auto host : whiteUrlHosts ) {
     addWhitelist( host );
   }
 }
@@ -17,11 +17,20 @@ GlobalBroadcaster * GlobalBroadcaster::instance()
 {
   return bdcaster;
 }
+
+void GlobalBroadcaster::insertCache( const QString & key, QByteArray * object )
+{
+  //do not cache the item when debug dictionary.
+  if ( preference->dictionaryDebug )
+    return;
+  cache.insert( key, object );
+}
+
 void GlobalBroadcaster::setPreference( Config::Preferences * p )
 {
   preference = p;
 }
-Config::Preferences * GlobalBroadcaster::getPreference()
+Config::Preferences * GlobalBroadcaster::getPreference() const
 {
   return preference;
 }
@@ -29,11 +38,11 @@ Config::Preferences * GlobalBroadcaster::getPreference()
 void GlobalBroadcaster::addWhitelist( QString url )
 {
   whitelist.insert( url );
-  auto baseUrl = Utils::Url::getHostBase( url );
+  const auto baseUrl = Utils::Url::getHostBase( url );
   whitelist.insert( baseUrl );
 }
 
-bool GlobalBroadcaster::existedInWhitelist( QString url )
+bool GlobalBroadcaster::existedInWhitelist( QString url ) const
 {
   return whitelist.contains( url );
 }
diff --git a/src/common/globalbroadcaster.hh b/src/common/globalbroadcaster.hh
index 41466164..ac51e02f 100644
--- a/src/common/globalbroadcaster.hh
+++ b/src/common/globalbroadcaster.hh
@@ -29,10 +29,10 @@ class GlobalBroadcaster: public QObject
 
 public:
   void setPreference( Config::Preferences * _pre );
-  Config::Preferences * getPreference();
+  Config::Preferences * getPreference() const;
   GlobalBroadcaster( QObject * parent = nullptr );
   void addWhitelist( QString host );
-  bool existedInWhitelist( QString host );
+  bool existedInWhitelist( QString host ) const;
   static GlobalBroadcaster * instance();
   unsigned currentGroupId;
   QString translateLineText{};
@@ -43,6 +43,8 @@ public:
   PronounceEngine pronounce_engine;
   QCache< QString, QByteArray > cache;
 
+  void insertCache( const QString &, QByteArray * );
+
 signals:
   void dictionaryChanges( ActiveDictIds ad );
   void dictionaryClear( ActiveDictIds ad );
diff --git a/src/config.cc b/src/config.cc
index 95376a01..c241be0f 100644
--- a/src/config.cc
+++ b/src/config.cc
@@ -494,6 +494,13 @@ void saveMutedDictionaries( QDomDocument & dd, QDomElement & muted, MutedDiction
 
 } // namespace
 
+bool fromConfig2Preference( const QDomNode & node, const QString & expectedValue, bool defaultValue = false )
+{
+  if ( !node.isNull() )
+    return ( node.toElement().text() == expectedValue );
+  return defaultValue;
+}
+
 Class load()
 {
   QString configName = getConfigFileName();
@@ -1005,6 +1012,8 @@ Class load()
       c.preferences.removeInvalidIndexOnExit =
         ( preferences.namedItem( "removeInvalidIndexOnExit" ).toElement().text() == "1" );
 
+    c.preferences.dictionaryDebug = fromConfig2Preference( preferences.namedItem( "dictionaryDebug" ), "1" );
+
     if ( !preferences.namedItem( "maxStringsInHistory" ).isNull() )
       c.preferences.maxStringsInHistory = preferences.namedItem( "maxStringsInHistory" ).toElement().text().toUInt();
 
@@ -1989,6 +1998,10 @@ void save( Class const & c )
     opt.appendChild( dd.createTextNode( c.preferences.removeInvalidIndexOnExit ? "1" : "0" ) );
     preferences.appendChild( opt );
 
+    opt = dd.createElement( "dictionaryDebug" );
+    opt.appendChild( dd.createTextNode( c.preferences.dictionaryDebug ? "1" : "0" ) );
+    preferences.appendChild( opt );
+
     opt = dd.createElement( "maxStringsInHistory" );
     opt.appendChild( dd.createTextNode( QString::number( c.preferences.maxStringsInHistory ) ) );
     preferences.appendChild( opt );
diff --git a/src/config.hh b/src/config.hh
index 2e7caa4e..4ec14bac 100644
--- a/src/config.hh
+++ b/src/config.hh
@@ -403,6 +403,7 @@ struct Preferences
   int maxNetworkCacheSize;
   bool clearNetworkCacheOnExit;
   bool removeInvalidIndexOnExit = false;
+  bool dictionaryDebug          = false;
 
   qreal zoomFactor;
   qreal helpZoomFactor;
diff --git a/src/dict/mdx.cc b/src/dict/mdx.cc
index b1d23936..78ff80cd 100644
--- a/src/dict/mdx.cc
+++ b/src/dict/mdx.cc
@@ -756,7 +756,7 @@ void MddResourceRequest::run()
         hasAnyData = true;
         data.resize( bytes->size() );
         memcpy( &data.front(), bytes->constData(), bytes->size() );
-        GlobalBroadcaster::instance()->cache.insert( unique_key, bytes );
+        GlobalBroadcaster::instance()->insertCache( unique_key, bytes );
         break;
       }
     }
@@ -790,7 +790,7 @@ void MddResourceRequest::run()
         data.resize( bytes.size() );
         memcpy( &data.front(), bytes.constData(), bytes.size() );
         //cache the processed css result to avoid process again.
-        GlobalBroadcaster::instance()->cache.insert( unique_key, new QByteArray( bytes ) );
+        GlobalBroadcaster::instance()->insertCache( unique_key, new QByteArray( bytes ) );
       }
       if ( Filetype::isNameOfTiff( u8ResourceName ) ) {
         // Convert it
diff --git a/src/ui/preferences.cc b/src/ui/preferences.cc
index 28c25716..69b8d694 100644
--- a/src/ui/preferences.cc
+++ b/src/ui/preferences.cc
@@ -347,6 +347,7 @@ Preferences::Preferences( QWidget * parent, Config::Class & cfg_ ):
 
   //Misc
   ui.removeInvalidIndexOnExit->setChecked( p.removeInvalidIndexOnExit );
+  ui.dictionaryDebug->setChecked( p.dictionaryDebug );
 
   // Add-on styles
   ui.addonStylesLabel->setVisible( ui.addonStyles->count() > 1 );
@@ -509,6 +510,7 @@ Config::Preferences Preferences::getPreferences()
   p.clearNetworkCacheOnExit       = ui.clearNetworkCacheOnExit->isChecked();
 
   p.removeInvalidIndexOnExit = ui.removeInvalidIndexOnExit->isChecked();
+  p.dictionaryDebug          = ui.dictionaryDebug->isChecked();
 
   p.addonStyle = ui.addonStyles->getCurrentStyle();
 
diff --git a/src/ui/preferences.ui b/src/ui/preferences.ui
index 614e8fce..4bd93f43 100644
--- a/src/ui/preferences.ui
+++ b/src/ui/preferences.ui
@@ -1960,6 +1960,16 @@ from Stardict, Babylon and GLS dictionaries</string>
             </property>
            </widget>
           </item>
+          <item>
+           <widget class="QCheckBox" name="dictionaryDebug">
+            <property name="toolTip">
+             <string>When debugging with dictionary css/js, disable certain cache to make it easier.</string>
+            </property>
+            <property name="text">
+             <string>Dictionary debug</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>