diff --git a/editor/js/Editor.js b/editor/js/Editor.js
index b758710..3d46c12 100755
--- a/editor/js/Editor.js
+++ b/editor/js/Editor.js
@@ -318,6 +318,39 @@ Editor.prototype = {
 		this.signals.animationSelected.dispatch( animation );
 
 	},
+	
+	duplicateAnimation: function(animation) {
+		
+		if (animation === undefined) {
+			
+			animation = this.selected;
+			if (animation === null) return;
+			
+		}
+
+		var offset = animation.end - animation.start;
+
+		var copy = new FRAME.Animation(
+			animation.name,
+			animation.start + offset,
+			animation.end + offset,
+			animation.layer,
+			animation.effect
+		);
+		
+		var overlap = this.getOverlappingAnimation(copy);
+		while (overlap) {
+			
+			copy.end = overlap.end + (copy.end - copy.start);
+			copy.start = overlap.end;
+			overlap = this.getOverlappingAnimation(copy);
+			
+		}
+
+		this.addAnimation(copy);
+		this.selectAnimation(copy);
+		
+	},
 
 	removeAnimation: function ( animation ) {
 
@@ -325,6 +358,20 @@ Editor.prototype = {
 		this.signals.animationRemoved.dispatch( animation );
 
 	},
+	
+	getOverlappingAnimation: function (animation) {
+		
+		for (let anim of this.timeline.animations) {
+			
+			if (anim.layer !== animation.layer || anim.id == animation.id) continue;
+			if ((anim.start <= animation.start && anim.end > animation.start) || 
+			    (anim.start < animation.end && anim.end > animation.end)) return anim;
+			
+		}
+		
+		return undefined;
+		
+	},
 
 	addCurve: function ( curve ) {
 
diff --git a/editor/js/Menubar.Edit.js b/editor/js/Menubar.Edit.js
index f69d8e9..a30c735 100755
--- a/editor/js/Menubar.Edit.js
+++ b/editor/js/Menubar.Edit.js
@@ -25,22 +25,7 @@ Menubar.Edit = function ( editor ) {
 	option.setTextContent( 'Duplicate' );
 	option.onClick( function () {
 
-		if ( editor.selected === null ) return;
-
-		var selected = editor.selected;
-
-		var offset = selected.end - selected.start;
-
-		var animation = new FRAME.Animation(
-			selected.name,
-			selected.start + offset,
-			selected.end + offset,
-			selected.layer,
-			selected.effect
-		);
-
-		editor.addAnimation( animation );
-		editor.selectAnimation( animation );
+		editor.duplicateAnimation();
 
 	} );
 	options.add( option );
diff --git a/editor/js/Timeline.Animations.js b/editor/js/Timeline.Animations.js
index f3a3677..fe5c2aa 100755
--- a/editor/js/Timeline.Animations.js
+++ b/editor/js/Timeline.Animations.js
@@ -34,33 +34,40 @@ Timeline.Animations = function ( editor ) {
 
 				movementX = event.movementX | event.webkitMovementX | event.mozMovementX | 0;
 
-				animation.start += movementX / scale;
-				animation.end += movementX / scale;
+				var pos = animation.getPosition();
+				pos.start += movementX / scale;
+				pos.end += movementX / scale;
 
-				if ( animation.start < 0 ) {
-
-					var offset = - animation.start;
-
-					animation.start += offset;
-					animation.end += offset;
+				if (pos.start < 0) {
+					
+					var offset = -animation.start;
 
+					pos.start += offset;
+					pos.end += offset;
+					
 				}
 
 				movementY += event.movementY | event.webkitMovementY | event.mozMovementY | 0;
 
-				if ( movementY >= 30 ) {
-
-					animation.layer = animation.layer + 1;
+				if (movementY >= 30) {
+					
+					pos.layer += 1;
 					movementY = 0;
-
+					
 				}
 
-				if ( movementY <= -30 ) {
-
-					animation.layer = Math.max( 0, animation.layer - 1 );
+				if (movementY <= -30) {
+					
+					pos.layer = Math.max(0, pos.layer - 1);
 					movementY = 0;
-
+					
 				}
+				
+				if (editor.getOverlappingAnimation(pos)) return false;
+				
+				animation.start = pos.start;
+				animation.end = pos.end;
+				animation.layer = pos.layer;
 
 				signals.animationModified.dispatch( animation );
 
@@ -78,44 +85,56 @@ Timeline.Animations = function ( editor ) {
 
 		}, false );
 
-		var resizeLeft = document.createElement( 'div' );
-		resizeLeft.style.position = 'absolute';
-		resizeLeft.style.width = '6px';
-		resizeLeft.style.height = '30px';
-		resizeLeft.style.cursor = 'w-resize';
-		resizeLeft.addEventListener( 'mousedown', function ( event ) {
-
+		var resizeOnMouseDown = function (event, left) {
+			
 			event.stopPropagation();
 
 			var movementX = 0;
 
-			function onMouseMove( event ) {
-
+			function onMouseMove(event) {
+				
 				movementX = event.movementX | event.webkitMovementX | event.mozMovementX | 0;
-
-				animation.start += movementX / scale;
-
-				signals.animationModified.dispatch( animation );
-
-			}
-
-			function onMouseUp( event ) {
-
-				if ( Math.abs( movementX ) < 2 ) {
-
-					editor.selectAnimation( animation );
-
+				
+				let pos = animation.getPosition();
+				
+				if (left) {
+					pos.start += movementX / scale;
+					if (pos.start > pos.end - 0.1) return;
+				}
+				else {
+					pos.end += movementX / scale;
+				}
+				
+				// If the animation would overlap any other on the same layer, don't increase the size.
+				if (editor.getOverlappingAnimation(pos)) return;
+				
+				if (left) {
+					animation.start = pos.start;
+				}
+				else {
+					animation.end = pos.end;
 				}
 
-				document.removeEventListener( 'mousemove', onMouseMove );
-				document.removeEventListener( 'mouseup', onMouseUp );
-
+				signals.animationModified.dispatch(animation);
 			}
+			
+			function onMouseUp(event) {
+				if (Math.abs(movementX) < 2) editor.selectAnimation(animation);
 
-			document.addEventListener( 'mousemove', onMouseMove, false );
-			document.addEventListener( 'mouseup', onMouseUp, false );
+				document.removeEventListener('mousemove', onMouseMove);
+				document.removeEventListener('mouseup', onMouseUp);
+			}
 
-		}, false );
+			document.addEventListener('mousemove', onMouseMove, false);
+			document.addEventListener('mouseup', onMouseUp, false);
+		}
+		
+		var resizeLeft = document.createElement( 'div' );
+		resizeLeft.style.position = 'absolute';
+		resizeLeft.style.width = '6px';
+		resizeLeft.style.height = '30px';
+		resizeLeft.style.cursor = 'w-resize';
+		resizeLeft.addEventListener( 'mousedown', (event) => resizeOnMouseDown(event, true), false );
 		dom.appendChild( resizeLeft );
 
 		var name = document.createElement( 'div' );
@@ -129,39 +148,7 @@ Timeline.Animations = function ( editor ) {
 		resizeRight.style.width = '6px';
 		resizeRight.style.height = '30px';
 		resizeRight.style.cursor = 'e-resize';
-		resizeRight.addEventListener( 'mousedown', function ( event ) {
-
-			event.stopPropagation();
-
-			var movementX = 0;
-
-			function onMouseMove( event ) {
-
-				movementX = event.movementX | event.webkitMovementX | event.mozMovementX | 0;
-
-				animation.end += movementX / scale;
-
-				signals.animationModified.dispatch( animation );
-
-			}
-
-			function onMouseUp( event ) {
-
-				if ( Math.abs( movementX ) < 2 ) {
-
-					editor.selectAnimation( animation );
-
-				}
-
-				document.removeEventListener( 'mousemove', onMouseMove );
-				document.removeEventListener( 'mouseup', onMouseUp );
-
-			}
-
-			document.addEventListener( 'mousemove', onMouseMove, false );
-			document.addEventListener( 'mouseup', onMouseUp, false );
-
-		}, false );
+		resizeRight.addEventListener( 'mousedown', (event) => resizeOnMouseDown(event, false), false );
 		dom.appendChild( resizeRight );
 
 		//
diff --git a/src/Frame.js b/src/Frame.js
index 37d35f6..83068ec 100755
--- a/src/Frame.js
+++ b/src/Frame.js
@@ -250,6 +250,17 @@ var FRAME = {
 			this.layer = layer;
 			this.effect = effect;
 			this.enabled = enabled;
+			
+			this.getPosition = function() {
+				
+				return {
+					start: this.start,
+					end: this.end,
+					layer: this.layer,
+					id: this.id
+				};
+				
+			};
 
 		};