diff --git a/Assets/LDtkUnity/Editor/CustomEditor/LDtkJsonEditorCache.cs b/Assets/LDtkUnity/Editor/CustomEditor/LDtkJsonEditorCache.cs
index bbab53fc..4655ba68 100644
--- a/Assets/LDtkUnity/Editor/CustomEditor/LDtkJsonEditorCache.cs
+++ b/Assets/LDtkUnity/Editor/CustomEditor/LDtkJsonEditorCache.cs
@@ -60,6 +60,10 @@ private void Reconstruct(LDtkProjectImporter importer, byte[] newHash)
             {
                 LDtkProfiler.EndWriting();
             }
+            
+            var preAction = new LDtkAssetProcessorActionCache();
+            LDtkAssetProcessorInvoker.AddPreProcessProject(preAction, fromJson, importer.AssetName, importer.assetPath);
+            preAction.Process();
 
             GlobalCache[_assetPath] = new LDtkJsonEditorCacheInstance()
             {
diff --git a/Assets/LDtkUnity/Editor/Postprocessing/LDtkAssetProcessorInvoker.cs b/Assets/LDtkUnity/Editor/Postprocessing/LDtkAssetProcessorInvoker.cs
index 9a2f738a..e87b0cda 100644
--- a/Assets/LDtkUnity/Editor/Postprocessing/LDtkAssetProcessorInvoker.cs
+++ b/Assets/LDtkUnity/Editor/Postprocessing/LDtkAssetProcessorInvoker.cs
@@ -20,12 +20,15 @@ private static void Reset()
             _preprocessors = null;
             _postprocessors = null;
         }
-        
-        public static void AddPreProcessProject(LDtkAssetProcessorActionCache cache, LdtkJson projectJson, string projectName) => 
-            AddPreprocessActions(cache, LDtkPreprocessor.METHOD_PROJECT, new object[]{projectJson, projectName});
-        
-        public static void AddPreProcessLevel(LDtkAssetProcessorActionCache cache, Level levelJson, LdtkJson projectJson, string projectName) => 
-            AddPreprocessActions(cache, LDtkPreprocessor.METHOD_LEVEL, new object[]{levelJson, projectJson, projectName});
+
+        public static void AddPreProcessProject(LDtkAssetProcessorActionCache cache, LdtkJson projectJson, string projectName, string assetPath) =>
+            AddPreprocessActions(cache, LDtkPreprocessor.METHOD_PROJECT, new object[] { projectJson, projectName, assetPath });
+
+        public static void AddPreProcessLevel(LDtkAssetProcessorActionCache cache, Level levelJson, LdtkJson projectJson, string projectName, string assetPath) =>
+            AddPreprocessActions(cache, LDtkPreprocessor.METHOD_LEVEL, new object[] { levelJson, projectJson, projectName, assetPath });
+
+        public static void AddPreProcessTilesetDef(LDtkAssetProcessorActionCache cache, LDtkTilesetDefinitionWrapper tilesetDefinition, string assetPath) =>
+            AddPreprocessActions(cache, LDtkPreprocessor.METHOD_TILESETDEF, new object[] { tilesetDefinition, assetPath });
         
         public static void AddPostProcessProject(LDtkAssetProcessorActionCache cache, LDtkJsonImporter importer, GameObject projectObj) => 
             AddPostprocessAction(cache, importer, LDtkPostprocessor.METHOD_PROJECT, new object[]{projectObj});
diff --git a/Assets/LDtkUnity/Editor/Postprocessing/LDtkPreprocessor.cs b/Assets/LDtkUnity/Editor/Postprocessing/LDtkPreprocessor.cs
index 2b59b616..060c2b0b 100644
--- a/Assets/LDtkUnity/Editor/Postprocessing/LDtkPreprocessor.cs
+++ b/Assets/LDtkUnity/Editor/Postprocessing/LDtkPreprocessor.cs
@@ -8,7 +8,8 @@ public abstract class LDtkPreprocessor
     {
         internal const string METHOD_PROJECT = nameof(OnPreprocessProject);
         internal const string METHOD_LEVEL = nameof(OnPreprocessLevel);
-        
+        internal const string METHOD_TILESETDEF = nameof(OnPreprocessTilesetDefinition);
+
         /// <summary>
         /// Use to perform operations before the project hierarchy is created.<br/>
         /// This is only called for project files, not separate level files.
@@ -19,7 +20,10 @@ public abstract class LDtkPreprocessor
         /// <param name="projectName">
         /// Name of the project file.
         /// </param>
-        protected virtual void OnPreprocessProject(LdtkJson projectJson, string projectName) { }
+        /// <param name="assetPath">
+        /// Path to the project file
+        /// </param>
+        protected virtual void OnPreprocessProject(LdtkJson projectJson, string projectName, string assetPath) { }
         
         /// <summary>
         /// Use to perform operations before the level hierarchy is created.<br/>
@@ -34,8 +38,22 @@ protected virtual void OnPreprocessProject(LdtkJson projectJson, string projectN
         /// <param name="projectName">
         /// Name of the project file.
         /// </param>
-        protected virtual void OnPreprocessLevel(Level level, LdtkJson projectJson, string projectName) { }
+        /// <param name="assetPath">
+        /// Path to the level file
+        /// </param>
+        protected virtual void OnPreprocessLevel(Level level, LdtkJson projectJson, string projectName, string assetPath) { }
 
+        /// <summary>
+        /// Use to perform operations before the tileset definition is created.<br/>
+        /// </summary>
+        /// <param name="tilesetDefinition">
+        /// The tileset definition json.
+        /// </param>
+        /// <param name="assetPath">
+        /// Path to the tileset definition file
+        /// </param>
+        protected virtual void OnPreprocessTilesetDefinition(LDtkTilesetDefinitionWrapper tilesetDefinition, string assetPath) { }
+        
         /// <summary>
         /// Override the order in which preprocessors are processed.
         /// All levels will only process after all projects. This is due to the way that Unity's import pipeline is structured.
diff --git a/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkLevelImporter.cs b/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkLevelImporter.cs
index 1b94bbfc..efd8d48b 100644
--- a/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkLevelImporter.cs
+++ b/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkLevelImporter.cs
@@ -127,10 +127,6 @@ private bool InitializeDefinitionObjects()
         
         private void BuildLevel()
         {
-            var preAction = new LDtkAssetProcessorActionCache();
-            LDtkAssetProcessorInvoker.AddPreProcessLevel(preAction, _levelJson, _projectJson, AssetName);
-            preAction.Process();
-            
             LDtkAssetProcessorActionCache assetProcess = new LDtkAssetProcessorActionCache();
 
             
@@ -190,6 +186,10 @@ private bool DeserializeAndAssign()
                 Logger.LogError(e.ToString());
                 return false;
             }
+            
+            var preAction = new LDtkAssetProcessorActionCache();
+            LDtkAssetProcessorInvoker.AddPreProcessLevel(preAction, _levelJson, _projectJson, AssetName, assetPath);
+            preAction.Process();
 
             return true;
         }
@@ -218,6 +218,10 @@ private static LdtkJson GetProjectJsonData(LDtkProjectImporter importer)
                 return null;
             }
             
+            var preAction = new LDtkAssetProcessorActionCache();
+            LDtkAssetProcessorInvoker.AddPreProcessProject(preAction, json, importer.AssetName, importer.assetPath);
+            preAction.Process();
+            
             if (Jsons.IsNullOrEmpty())
             {
                 //Debug.Log("Added delayCall, this should only be called once per mass-reimport instance");
diff --git a/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkProjectImporter.cs b/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkProjectImporter.cs
index 8fd12665..1b36673c 100644
--- a/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkProjectImporter.cs
+++ b/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkProjectImporter.cs
@@ -223,13 +223,17 @@ private static void CheckDefaultEditorBehaviour()
         private bool TryGetJson(out LdtkJson json)
         {
             json = FromJson<LdtkJson>();
-            if (json != null)
+            if (json == null)
             {
-                return true;
+                Logger.LogError("LDtk: Json import error");
+                return false;
             }
 
-            Logger.LogError("LDtk: Json import error");
-            return false;
+            var preAction = new LDtkAssetProcessorActionCache();
+            LDtkAssetProcessorInvoker.AddPreProcessProject(preAction, json, AssetName, assetPath);
+            preAction.Process();
+
+            return true;
         }
 
         private void CreateJsonAsset()
@@ -306,15 +310,6 @@ private void BufferEditorCache()
 
         private void MainBuild(LdtkJson json)
         {
-            LDtkProfiler.BeginSample("SetupPreprocessors");
-            var preAction = new LDtkAssetProcessorActionCache();
-            LDtkAssetProcessorInvoker.AddPreProcessProject(preAction, json, AssetName);
-            LDtkProfiler.EndSample();
-            
-            LDtkProfiler.BeginSample("RunPreprocessors");
-            preAction.Process();
-            LDtkProfiler.EndSample();
-            
             LDtkProfiler.BeginSample("ImportProject");
             LDtkBuilderProjectFactory factory = new LDtkBuilderProjectFactory(this);
             factory.Import(json);
diff --git a/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkTilesetImporter.cs b/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkTilesetImporter.cs
index 655b4e21..24d67a83 100644
--- a/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkTilesetImporter.cs
+++ b/Assets/LDtkUnity/Editor/ScriptedImporter/LDtkTilesetImporter.cs
@@ -304,6 +304,11 @@ private bool DeserializeAndAssign()
             try
             {
                 _definition = FromJson<LDtkTilesetDefinitionWrapper>();
+
+                var preAction = new LDtkAssetProcessorActionCache();
+                LDtkAssetProcessorInvoker.AddPreProcessTilesetDef(preAction, _definition, assetPath);
+                preAction.Process();
+
                 _json = _definition.Def;
             }
             catch (Exception e)
@@ -494,7 +499,13 @@ private static string PathToTexture(string assetPath, TilesetDefinition def = nu
             
             if (def == null)
             {
-                def = FromJson<LDtkTilesetDefinitionWrapper>(assetPath).Def;
+                LDtkTilesetDefinitionWrapper wrapper = FromJson<LDtkTilesetDefinitionWrapper>(assetPath);
+                
+                var preAction = new LDtkAssetProcessorActionCache();
+                LDtkAssetProcessorInvoker.AddPreProcessTilesetDef(preAction, wrapper, assetPath);
+                preAction.Process();
+                
+                def = wrapper.Def;
             }
             
             if (def.IsEmbedAtlas)