diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 5bbcff1eb..ad25b6eea 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -883,6 +883,119 @@ void DivEngine::clearSubSongs() {
   BUSY_END;
 }
 
+void DivEngine::delUnusedIns() {
+  BUSY_BEGIN;
+  saveLock.lock();
+
+  bool isUsed[256];
+  memset(isUsed,0,256*sizeof(bool));
+
+  // scan
+  for (int i=0; i<chans; i++) {
+    for (size_t j=0; j<song.subsong.size(); j++) {
+      for (int k=0; k<DIV_MAX_PATTERNS; k++) {
+        if (song.subsong[j]->pat[i].data[k]==NULL) continue;
+        for (int l=0; l<song.subsong[j]->patLen; l++) {
+          if (song.subsong[j]->pat[i].data[k]->data[l][2]>=0 && song.subsong[j]->pat[i].data[k]->data[l][2]<256) {
+            isUsed[song.subsong[j]->pat[i].data[k]->data[l][2]]=true;
+          }
+        }
+      }
+    }
+  }
+  
+  // delete
+  for (int i=0; i<song.insLen; i++) {
+    if (!isUsed[i]) {
+      delInstrumentUnsafe(i);
+      // rotate
+      for (int j=i; j<255; j++) {
+        isUsed[j]=isUsed[j+1];
+      }
+      isUsed[255]=true;
+      i--;
+    }
+  }
+
+  saveLock.unlock();
+  BUSY_END;
+}
+
+void DivEngine::delUnusedWaves() {
+  BUSY_BEGIN;
+  saveLock.lock();
+
+  saveLock.unlock();
+  BUSY_END;
+}
+
+void DivEngine::delUnusedSamples() {
+  BUSY_BEGIN;
+  saveLock.lock();
+
+  bool isUsed[256];
+  memset(isUsed,0,256*sizeof(bool));
+
+  // scan
+  for (DivInstrument* i: song.ins) {
+    if ((i->type==DIV_INS_PCE && i->amiga.useSample) ||
+        i->type==DIV_INS_MSM6258 ||
+        i->type==DIV_INS_MSM6295 ||
+        i->type==DIV_INS_ADPCMA ||
+        i->type==DIV_INS_ADPCMB ||
+        i->type==DIV_INS_SEGAPCM ||
+        i->type==DIV_INS_QSOUND ||
+        i->type==DIV_INS_YMZ280B ||
+        i->type==DIV_INS_RF5C68 ||
+        i->type==DIV_INS_AMIGA ||
+        i->type==DIV_INS_MULTIPCM ||
+        (i->type==DIV_INS_MIKEY && i->amiga.useSample) ||
+        (i->type==DIV_INS_X1_010 && i->amiga.useSample) ||
+        (i->type==DIV_INS_SWAN && i->amiga.useSample) ||
+        (i->type==DIV_INS_AY && i->amiga.useSample) ||
+        (i->type==DIV_INS_AY8930 && i->amiga.useSample) ||
+        (i->type==DIV_INS_VRC6 && i->amiga.useSample) ||
+        (i->type==DIV_INS_SU && i->amiga.useSample) ||
+        i->type==DIV_INS_SNES ||
+        i->type==DIV_INS_ES5506 ||
+        i->type==DIV_INS_K007232 ||
+        i->type==DIV_INS_GA20 ||
+        i->type==DIV_INS_K053260 ||
+        i->type==DIV_INS_C140 ||
+        i->type==DIV_INS_C219) {
+      if (i->amiga.initSample>=0 && i->amiga.initSample<song.sampleLen) {
+        isUsed[i->amiga.initSample]=true;
+      }
+      if (i->amiga.useNoteMap) {
+        for (int j=0; j<120; j++) {
+          if (i->amiga.noteMap[j].map>=0 && i->amiga.noteMap[j].map<song.sampleLen) {
+            isUsed[i->amiga.noteMap[j].map]=true;
+          }
+        }
+      }
+    }
+  }
+
+  // delete
+  for (int i=0; i<song.sampleLen; i++) {
+    if (!isUsed[i]) {
+      delSampleUnsafe(i,false);
+      // rotate
+      for (int j=i; j<255; j++) {
+        isUsed[j]=isUsed[j+1];
+      }
+      isUsed[255]=true;
+      i--;
+    }
+  }
+
+  // render
+  renderSamples();
+
+  saveLock.unlock();
+  BUSY_END;
+}
+
 void DivEngine::changeSystem(int index, DivSystem which, bool preserveOrder) {
   int chanCount=chans;
   quitDispatch();
@@ -2239,9 +2352,7 @@ void DivEngine::loadTempIns(DivInstrument* which) {
   BUSY_END;
 }
 
-void DivEngine::delInstrument(int index) {
-  BUSY_BEGIN;
-  saveLock.lock();
+void DivEngine::delInstrumentUnsafe(int index) {
   if (index>=0 && index<(int)song.ins.size()) {
     for (int i=0; i<song.systemLen; i++) {
       disCont[i].dispatch->notifyInsDeletion(song.ins[index]);
@@ -2264,6 +2375,12 @@ void DivEngine::delInstrument(int index) {
     removeAsset(song.insDir,index);
     checkAssetDir(song.insDir,song.ins.size());
   }
+}
+
+void DivEngine::delInstrument(int index) {
+  BUSY_BEGIN;
+  saveLock.lock();
+  delInstrumentUnsafe(index);
   saveLock.unlock();
   BUSY_END;
 }
@@ -2444,9 +2561,7 @@ DivWavetable* DivEngine::waveFromFile(const char* path, bool addRaw) {
   return wave;
 }
 
-void DivEngine::delWave(int index) {
-  BUSY_BEGIN;
-  saveLock.lock();
+void DivEngine::delWaveUnsafe(int index) {
   if (index>=0 && index<(int)song.wave.size()) {
     delete song.wave[index];
     song.wave.erase(song.wave.begin()+index);
@@ -2454,6 +2569,12 @@ void DivEngine::delWave(int index) {
     removeAsset(song.waveDir,index);
     checkAssetDir(song.waveDir,song.wave.size());
   }
+}
+
+void DivEngine::delWave(int index) {
+  BUSY_BEGIN;
+  saveLock.lock();
+  delWaveUnsafe(index);
   saveLock.unlock();
   BUSY_END;
 }
@@ -2498,12 +2619,10 @@ int DivEngine::addSamplePtr(DivSample* which) {
   return sampleCount;
 }
 
-void DivEngine::delSample(int index) {
-  BUSY_BEGIN;
+void DivEngine::delSampleUnsafe(int index, bool render) {
   sPreview.sample=-1;
   sPreview.pos=0;
   sPreview.dir=false;
-  saveLock.lock();
   if (index>=0 && index<(int)song.sample.size()) {
     delete song.sample[index];
     song.sample.erase(song.sample.begin()+index);
@@ -2527,8 +2646,14 @@ void DivEngine::delSample(int index) {
       }
     }
 
-    renderSamples();
+    if (render) renderSamples();
   }
+}
+
+void DivEngine::delSample(int index) {
+  BUSY_BEGIN;
+  saveLock.lock();
+  delSampleUnsafe(index);
   saveLock.unlock();
   BUSY_END;
 }
diff --git a/src/engine/engine.h b/src/engine/engine.h
index c1b760bdf..914a207dd 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -889,6 +889,7 @@ class DivEngine {
 
     // delete instrument
     void delInstrument(int index);
+    void delInstrumentUnsafe(int index);
 
     // add wavetable
     int addWave();
@@ -901,6 +902,7 @@ class DivEngine {
 
     // delete wavetable
     void delWave(int index);
+    void delWaveUnsafe(int index);
 
     // add sample
     int addSample();
@@ -916,6 +918,7 @@ class DivEngine {
 
     // delete sample
     void delSample(int index);
+    void delSampleUnsafe(int index, bool render=true);
 
     // add order
     void addOrder(int pos, bool duplicate, bool where);
@@ -1095,6 +1098,11 @@ class DivEngine {
     // clear all subsong data
     void clearSubSongs();
 
+    // optimize assets
+    void delUnusedIns();
+    void delUnusedWaves();
+    void delUnusedSamples();
+
     // change system
     void changeSystem(int index, DivSystem which, bool preserveOrder=true);
 
diff --git a/src/gui/doAction.cpp b/src/gui/doAction.cpp
index ebb26cac9..6edfa694d 100644
--- a/src/gui/doAction.cpp
+++ b/src/gui/doAction.cpp
@@ -183,7 +183,7 @@ void FurnaceGUI::doAction(int what) {
       e->syncReset();
       break;
     case GUI_ACTION_CLEAR:
-      showWarning("Are you sure you want to clear... (cannot be undone!)",GUI_WARN_CLEAR);
+      showWarning("Select an option: (cannot be undone!)",GUI_WARN_CLEAR);
       break;
 
     case GUI_ACTION_WINDOW_EDIT_CONTROLS:
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 176e99a02..af2d4458c 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -5521,90 +5521,144 @@ bool FurnaceGUI::loop() {
           }
           break;
         case GUI_WARN_CLEAR:
-          if (ImGui::Button("All subsongs")) {
-            stop();
-            e->clearSubSongs();
-            curOrder=0;
-            oldOrder=0;
-            oldOrder1=0;
-            MARK_MODIFIED;
-            ImGui::CloseCurrentPopup();
-          }
-          ImGui::SameLine();
-          if (ImGui::Button("Current subsong")) {
-            stop();
-            e->lockEngine([this]() {
-              e->curSubSong->clearData();
-            });
-            e->setOrder(0);
-            curOrder=0;
-            oldOrder=0;
-            oldOrder1=0;
-            MARK_MODIFIED;
-            ImGui::CloseCurrentPopup();
-          }
-          ImGui::SameLine();
-          if (ImGui::Button("Orders")) {
-            stop();
-            e->lockEngine([this]() {
-              memset(e->curOrders->ord,0,DIV_MAX_CHANS*DIV_MAX_PATTERNS);
-              e->curSubSong->ordersLen=1;
-            });
-            e->setOrder(0);
-            curOrder=0;
-            oldOrder=0;
-            oldOrder1=0;
-            MARK_MODIFIED;
-            ImGui::CloseCurrentPopup();
-          }
-          ImGui::SameLine();
-          if (ImGui::Button("Pattern")) {
-            stop();
-            e->lockEngine([this]() {
-              for (int i=0; i<e->getTotalChannelCount(); i++) {
-                DivPattern* pat=e->curPat[i].getPattern(e->curOrders->ord[i][curOrder],true);
-                memset(pat->data,-1,DIV_MAX_ROWS*DIV_MAX_COLS*sizeof(short));
-                for (int j=0; j<DIV_MAX_ROWS; j++) {
-                  pat->data[j][0]=0;
-                  pat->data[j][1]=0;
+          if (ImGui::BeginTable("EraseOpt",2,ImGuiTableFlags_BordersInnerV)) {
+            ImGui::TableSetupColumn("c0",ImGuiTableColumnFlags_WidthStretch,0.5f);
+            ImGui::TableSetupColumn("c1",ImGuiTableColumnFlags_WidthStretch,0.5f);
+            ImGui::TableNextRow();
+
+            ImGui::TableNextColumn();
+            ImGui::PushFont(headFont);
+            ImGui::AlignTextToFramePadding();
+            ImGui::Text("Erasing");
+            ImGui::PopFont();
+
+            if (ImGui::Button("All subsongs")) {
+              stop();
+              e->clearSubSongs();
+              curOrder=0;
+              oldOrder=0;
+              oldOrder1=0;
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+            if (ImGui::Button("Current subsong")) {
+              stop();
+              e->lockEngine([this]() {
+                e->curSubSong->clearData();
+              });
+              e->setOrder(0);
+              curOrder=0;
+              oldOrder=0;
+              oldOrder1=0;
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+            if (ImGui::Button("Orders")) {
+              stop();
+              e->lockEngine([this]() {
+                memset(e->curOrders->ord,0,DIV_MAX_CHANS*DIV_MAX_PATTERNS);
+                e->curSubSong->ordersLen=1;
+              });
+              e->setOrder(0);
+              curOrder=0;
+              oldOrder=0;
+              oldOrder1=0;
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+            if (ImGui::Button("Pattern")) {
+              stop();
+              e->lockEngine([this]() {
+                for (int i=0; i<e->getTotalChannelCount(); i++) {
+                  DivPattern* pat=e->curPat[i].getPattern(e->curOrders->ord[i][curOrder],true);
+                  memset(pat->data,-1,DIV_MAX_ROWS*DIV_MAX_COLS*sizeof(short));
+                  for (int j=0; j<DIV_MAX_ROWS; j++) {
+                    pat->data[j][0]=0;
+                    pat->data[j][1]=0;
+                  }
                 }
-              }
-            });
-            MARK_MODIFIED;
-            ImGui::CloseCurrentPopup();
-          }
-          ImGui::SameLine();
-          if (ImGui::Button("Instruments")) {
-            stop();
-            e->lockEngine([this]() {
-              e->song.clearInstruments();
-            });
-            curIns=-1;
-            MARK_MODIFIED;
-            ImGui::CloseCurrentPopup();
-          }
-          ImGui::SameLine();
-          if (ImGui::Button("Wavetables")) {
-            stop();
-            e->lockEngine([this]() {
-              e->song.clearWavetables();
-            });
-            curWave=0;
-            MARK_MODIFIED;
-            ImGui::CloseCurrentPopup();
-          }
-          ImGui::SameLine();
-          if (ImGui::Button("Samples")) {
-            stop();
-            e->lockEngine([this]() {
-              e->song.clearSamples();
-            });
-            curSample=0;
-            ImGui::CloseCurrentPopup();
+              });
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+            if (ImGui::Button("Instruments")) {
+              stop();
+              e->lockEngine([this]() {
+                e->song.clearInstruments();
+              });
+              curIns=-1;
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+            if (ImGui::Button("Wavetables")) {
+              stop();
+              e->lockEngine([this]() {
+                e->song.clearWavetables();
+              });
+              curWave=0;
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+            if (ImGui::Button("Samples")) {
+              stop();
+              e->lockEngine([this]() {
+                e->song.clearSamples();
+              });
+              curSample=0;
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+
+            ImGui::TableNextColumn();
+            ImGui::PushFont(headFont);
+            ImGui::AlignTextToFramePadding();
+            ImGui::Text("Optimization");
+            ImGui::PopFont();
+
+            if (ImGui::Button("De-duplicate patterns")) {
+              stop();
+              e->lockEngine([this]() {
+                e->curSubSong->optimizePatterns();
+                e->curSubSong->rearrangePatterns();
+              });
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+            if (ImGui::Button("Remove unused instruments")) {
+              stop();
+              e->delUnusedIns();
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+            /*
+            if (ImGui::Button("Remove unused wavetables")) {
+              stop();
+              e->delUnusedWaves();
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }*/
+            if (ImGui::Button("Remove unused samples")) {
+              stop();
+              e->delUnusedSamples();
+              MARK_MODIFIED;
+              ImGui::CloseCurrentPopup();
+            }
+
+            ImGui::EndTable();
           }
 
-          if (ImGui::Button("Wait! What am I doing? Cancel!") || ImGui::IsKeyPressed(ImGuiKey_Escape)) {
-            ImGui::CloseCurrentPopup();
+          if (ImGui::BeginTable("EraseOptFooter",3)) {
+            ImGui::TableSetupColumn("c0",ImGuiTableColumnFlags_WidthStretch,0.5f);
+            ImGui::TableSetupColumn("c1",ImGuiTableColumnFlags_WidthFixed);
+            ImGui::TableSetupColumn("c2",ImGuiTableColumnFlags_WidthStretch,0.5f);
+            ImGui::TableNextRow();
+            ImGui::TableNextColumn();
+            ImGui::TableNextColumn();
+            if (ImGui::Button("Never mind! Cancel") || ImGui::IsKeyPressed(ImGuiKey_Escape)) {
+              ImGui::CloseCurrentPopup();
+            }
+            ImGui::TableNextColumn();
+            ImGui::EndTable();
           }
           break;
         case GUI_WARN_SUBSONG_DEL: