diff --git a/effects.cpp b/effects.cpp
index 5efcfd2a0e..bb382e95a0 100644
--- a/effects.cpp
+++ b/effects.cpp
@@ -1638,11 +1638,23 @@ QString EffectsHandlerImpl::supportInformation(const QString &name) const
     return QString();
 }
 
+
 bool EffectsHandlerImpl::isScreenLocked() const
 {
     return m_screenLockerWatcher->isLocked();
 }
 
+QString EffectsHandlerImpl::debug(const QString& name, const QString& parameter) const
+{
+    QString internalName = name.startsWith("kwin4_effect_") ? name : "kwin4_effect_" + name;
+    for (QVector< EffectPair >::const_iterator it = loaded_effects.constBegin(); it != loaded_effects.constEnd(); ++it) {
+        if ((*it).first == internalName) {
+            return it->second->debug(parameter);
+        }
+    }
+    return QString();
+}
+
 //****************************************
 // EffectWindowImpl
 //****************************************
diff --git a/effects.h b/effects.h
index a513665011..2cd4c43021 100644
--- a/effects.h
+++ b/effects.h
@@ -193,6 +193,7 @@ public Q_SLOTS:
     Q_SCRIPTABLE void unloadEffect(const QString& name);
     Q_SCRIPTABLE bool isEffectLoaded(const QString& name) const;
     Q_SCRIPTABLE QString supportInformation(const QString& name) const;
+    Q_SCRIPTABLE QString debug(const QString& name, const QString& parameter = QString()) const;
 
 protected Q_SLOTS:
     void slotDesktopChanged(int old, KWin::Client *withClient);
diff --git a/libkwineffects/anidata.cpp b/libkwineffects/anidata.cpp
index cc0d872e7f..09635b03d6 100644
--- a/libkwineffects/anidata.cpp
+++ b/libkwineffects/anidata.cpp
@@ -22,6 +22,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <KDebug>
 
+QDebug operator<<(QDebug dbg, const KWin::AniData &a)
+{
+    dbg.nospace() << a.debugInfo();
+    return dbg.space();
+}
+
 using namespace KWin;
 static int Gaussian = 46;
 
@@ -158,6 +164,22 @@ AniData::AniData(const QString &str) // format: WindowMask:Attribute:Meta:Durati
     }
 }
 
+static QString attributeString(KWin::AnimationEffect::Attribute attribute)
+{
+    switch (attribute) {
+    case KWin::AnimationEffect::Opacity:      return "Opacity";
+    case KWin::AnimationEffect::Brightness:   return "Brightness";
+    case KWin::AnimationEffect::Saturation:   return "Saturation";
+    case KWin::AnimationEffect::Scale:        return "Scale";
+    case KWin::AnimationEffect::Translation:  return "Translation";
+    case KWin::AnimationEffect::Rotation:     return "Rotation";
+    case KWin::AnimationEffect::Position:     return "Position";
+    case KWin::AnimationEffect::Size:         return "Size";
+    case KWin::AnimationEffect::Clip:         return "Clip";
+    default:                                  return " ";
+    }
+}
+
 QList<AniData> AniData::list(const QString &str)
 {
     QList<AniData> newList;
@@ -172,21 +194,20 @@ QList<AniData> AniData::list(const QString &str)
 
 QString AniData::toString() const
 {
-    QString ret = QString::number((uint)windowType) + ':';
-    switch (attribute) {
-    case AnimationEffect::Opacity:      ret += "Opacity:"; break;
-    case AnimationEffect::Brightness:   ret += "Brightness:"; break;
-    case AnimationEffect::Saturation:   ret += "Saturation:"; break;
-    case AnimationEffect::Scale:        ret += "Scale:"; break;
-    case AnimationEffect::Translation:  ret += "Translation:"; break;
-    case AnimationEffect::Rotation:     ret += "Rotation:"; break;
-    case AnimationEffect::Position:     ret += "Position:"; break;
-    case AnimationEffect::Size:         ret += "Size:"; break;
-    case AnimationEffect::Clip:         ret += "Clip:"; break;
-    default:                            ret += ':';
-    }
-    ret +=  QString::number(meta) + ':' + QString::number(duration) + ':' +
-            to.toString() + ':' + QString::number(customCurve) + ':' +
-            QString::number(time) + ':' + from.toString();
+    QString ret =   QString::number((uint)windowType) + ':' + attributeString(attribute) + ':' +
+                    QString::number(meta) + ':' + QString::number(duration) + ':' +
+                    to.toString() + ':' + QString::number(customCurve) + ':' +
+                    QString::number(time) + ':' + from.toString();
     return ret;
 }
+
+QString AniData::debugInfo() const
+{
+    return "Animation: " + attributeString(attribute) + '\n' +
+           "     From: " + from.toString() + '\n' +
+           "       To: " + to.toString() + '\n' +
+           "  Started: " + QString::number(AnimationEffect::clock() - startTime) + "ms ago\n" +
+           " Duration: " + QString::number(duration) + "ms\n" +
+           "   Passed: " + QString::number(time) + "ms\n" +
+           " Applying: " + QString::number(windowType) + '\n';
+}
diff --git a/libkwineffects/anidata_p.h b/libkwineffects/anidata_p.h
index b2c704912c..75c7f47fb9 100644
--- a/libkwineffects/anidata_p.h
+++ b/libkwineffects/anidata_p.h
@@ -40,6 +40,7 @@ public:
     }
     static QList<AniData> list(const QString &str);
     QString toString() const;
+    QString debugInfo() const;
     AnimationEffect::Attribute attribute;
     QEasingCurve curve;
     int customCurve;
@@ -53,4 +54,6 @@ public:
 
 } // namespace
 
+QDebug operator<<(QDebug dbg, const KWin::AniData &a);
+
 #endif // ANIDATA_H
diff --git a/libkwineffects/kwinanimationeffect.cpp b/libkwineffects/kwinanimationeffect.cpp
index e8bc44e977..a411b19a61 100644
--- a/libkwineffects/kwinanimationeffect.cpp
+++ b/libkwineffects/kwinanimationeffect.cpp
@@ -23,8 +23,15 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <QDateTime>
 #include <QTimer>
+#include <QtDebug>
 #include <QVector3D>
 
+QDebug operator<<(QDebug dbg, const KWin::FPx2 &fpx2)
+{
+    dbg.nospace() << fpx2[0] << "," << fpx2[1] << QString(fpx2.isValid() ? " (valid)" : " (invalid)");
+    return dbg.space();
+}
+
 namespace KWin {
 
 QElapsedTimer AnimationEffect::s_clock;
@@ -824,4 +831,26 @@ void AnimationEffect::_windowDeleted( EffectWindow* w )
 }
 
 
+QString AnimationEffect::debug(const QString &/*parameter*/) const
+{
+    Q_D(const AnimationEffect);
+    QString dbg;
+    if (d->m_animations.isEmpty())
+        dbg = "No window is animated";
+    else {
+        AniMap::const_iterator entry = d->m_animations.constBegin(), mapEnd = d->m_animations.constEnd();
+        for (; entry != mapEnd; ++entry) {
+            QString caption = entry.key()->isDeleted() ? "[Deleted]" : entry.key()->caption();
+            if (caption.isEmpty())
+                caption = "[Untitled]";
+            dbg += "Animating window: " + caption + '\n';
+            QList<AniData>::const_iterator anim = entry->first.constBegin(), animEnd = entry->first.constEnd();
+            for (; anim != animEnd; ++anim)
+                dbg += anim->debugInfo();
+        }
+    }
+    return dbg;
+}
+
+
 #include "moc_kwinanimationeffect.cpp"
diff --git a/libkwineffects/kwinanimationeffect.h b/libkwineffects/kwinanimationeffect.h
index c5e2d2d757..08c34934d3 100644
--- a/libkwineffects/kwinanimationeffect.h
+++ b/libkwineffects/kwinanimationeffect.h
@@ -81,6 +81,7 @@ public:
 
     inline void set(float v) { f[0] = v; valid = true; }
     inline void set(float v1, float v2) { f[0] = v1; f[1] = v2; valid = true; }
+
 private:
     float f[2];
     bool valid;
@@ -125,6 +126,7 @@ public:
     /**
      * Reimplemented from KWIn::Effect
      */
+    QString debug(const QString &parameter) const;
     virtual void prePaintScreen( ScreenPrePaintData& data, int time );
     virtual void prePaintWindow( EffectWindow* w, WindowPrePaintData& data, int time );
     virtual void paintWindow( EffectWindow* w, int mask, QRegion region, WindowPaintData& data );
@@ -211,6 +213,7 @@ private:
 
 
 } // namespace
+QDebug operator<<(QDebug dbg, const KWin::FPx2 &fpx2);
 Q_DECLARE_METATYPE(KWin::FPx2)
 
 #endif // ANIMATION_EFFECT_H
diff --git a/libkwineffects/kwineffects.cpp b/libkwineffects/kwineffects.cpp
index 191cc52cc8..0cc83c3abe 100644
--- a/libkwineffects/kwineffects.cpp
+++ b/libkwineffects/kwineffects.cpp
@@ -527,6 +527,11 @@ bool Effect::isActive() const
     return true;
 }
 
+QString Effect::debug(const QString &) const
+{
+    return QString();
+}
+
 void Effect::drawWindow(EffectWindow* w, int mask, QRegion region, WindowPaintData& data)
 {
     effects->drawWindow(w, mask, region, data);
diff --git a/libkwineffects/kwineffects.h b/libkwineffects/kwineffects.h
index 9c66067194..f6a8ed6710 100644
--- a/libkwineffects/kwineffects.h
+++ b/libkwineffects/kwineffects.h
@@ -170,7 +170,7 @@ X-KDE-Library=kwin4_effect_cooleffect
 
 #define KWIN_EFFECT_API_MAKE_VERSION( major, minor ) (( major ) << 8 | ( minor ))
 #define KWIN_EFFECT_API_VERSION_MAJOR 0
-#define KWIN_EFFECT_API_VERSION_MINOR 221
+#define KWIN_EFFECT_API_VERSION_MINOR 222
 #define KWIN_EFFECT_API_VERSION KWIN_EFFECT_API_MAKE_VERSION( \
         KWIN_EFFECT_API_VERSION_MAJOR, KWIN_EFFECT_API_VERSION_MINOR )
 
@@ -454,6 +454,19 @@ public:
      **/
     virtual bool isActive() const;
 
+    /**
+     * Reimplement this method to provide online debugging.
+     * This could be as trivial as printing specific detail informations about the effect state
+     * but could also be used to move the effect in and out of a special debug modes, clear bogus
+     * data, etc.
+     * Notice that the functions is const by intent! Whenever you alter the state of the object
+     * due to random user input, you should do so with greatest care, hence const_cast<> your
+     * object - signalling "let me alone, i know what i'm doing"
+     * @param parameter A freeform string user input for your effect to interpret.
+     * @since 4.11
+     */
+    virtual QString debug(const QString &parameter) const;
+
     static int displayWidth();
     static int displayHeight();
     static QPoint cursorPos();
diff --git a/org.kde.kwin.Effects.xml b/org.kde.kwin.Effects.xml
index d060e8e023..4456743973 100644
--- a/org.kde.kwin.Effects.xml
+++ b/org.kde.kwin.Effects.xml
@@ -30,5 +30,10 @@
       <arg type="s" direction="out"/>
       <arg name="name" type="s" direction="in"/>
     </method>
+    <method name="debug">
+      <arg type="s" direction="out"/>
+      <arg name="name" type="s" direction="in"/>
+      <arg name="name" type="s" direction="in"/>
+    </method>
   </interface>
 </node>