diff --git a/examples/test.jGIS b/examples/test.jGIS
index 973ddd16..b2442787 100644
--- a/examples/test.jGIS
+++ b/examples/test.jGIS
@@ -1,40 +1,69 @@
 {
+  "layerTree": [
+    "a0044fd7-f167-445f-b3d1-620a8f94b498",
+    {
+      "layers": [
+        "2467576f-b527-4cb7-998d-fa1d056fb8a1",
+        {
+          "layers": [
+            "57ef55ef-facb-48a2-ae1d-c9c824be3e8a"
+          ],
+          "name": "level 2 group"
+        }
+      ],
+      "name": "level 1 group"
+    }
+  ],
   "layers": {
+    "2467576f-b527-4cb7-998d-fa1d056fb8a1": {
+      "name": "Open Street Map",
+      "parameters": {
+        "source": "699facc9-e7c4-4f38-acf1-1fd7f02d9f36"
+      },
+      "type": "RasterLayer",
+      "visible": true
+    },
     "57ef55ef-facb-48a2-ae1d-c9c824be3e8a": {
+      "name": "Regions France",
       "parameters": {
-        "source": "7d082e75-69d5-447a-82d8-b05cca5945ba",
-        "type": "line",
         "color": "#e66100",
-        "opacity": 0.6
+        "opacity": 0.6,
+        "source": "7d082e75-69d5-447a-82d8-b05cca5945ba",
+        "type": "line"
       },
-      "name": "Regions France",
-      "visible": true,
-      "type": "VectorLayer"
+      "type": "VectorLayer",
+      "visible": true
     },
     "a0044fd7-f167-445f-b3d1-620a8f94b498": {
-      "type": "RasterLayer",
-      "visible": true,
       "name": "Open Topo Map",
       "parameters": {
         "source": "5fd42e3b-4681-4607-b15d-65c3a3e89b32"
-      }
-    },
-    "2467576f-b527-4cb7-998d-fa1d056fb8a1": {
-      "parameters": {
-        "source": "699facc9-e7c4-4f38-acf1-1fd7f02d9f36"
       },
       "type": "RasterLayer",
-      "name": "Open Street Map",
       "visible": true
     }
   },
+  "options": {
+    "latitude": 45.83799886047626,
+    "longitude": 1.195999428191726,
+    "zoom": 4.075821017792898
+  },
   "sources": {
     "5fd42e3b-4681-4607-b15d-65c3a3e89b32": {
       "name": "Open Topo Map",
       "parameters": {
+        "maxZoom": 24.0,
         "minZoom": 0.0,
-        "url": "https://tile.opentopomap.org/{z}/{x}/{y}.png ",
-        "maxZoom": 24.0
+        "url": "https://tile.opentopomap.org/{z}/{x}/{y}.png "
+      },
+      "type": "RasterSource"
+    },
+    "699facc9-e7c4-4f38-acf1-1fd7f02d9f36": {
+      "name": "Open Street Map",
+      "parameters": {
+        "maxZoom": 24.0,
+        "minZoom": 0.0,
+        "url": "https://tile.openstreetmap.org/{z}/{x}/{y}.png"
       },
       "type": "RasterSource"
     },
@@ -45,35 +74,6 @@
         "valid": true
       },
       "type": "GeoJSONSource"
-    },
-    "699facc9-e7c4-4f38-acf1-1fd7f02d9f36": {
-      "type": "RasterSource",
-      "name": "Open Street Map",
-      "parameters": {
-        "minZoom": 0.0,
-        "maxZoom": 24.0,
-        "url": "https://tile.openstreetmap.org/{z}/{x}/{y}.png"
-      }
-    }
-  },
-  "options": {
-    "latitude": 0,
-    "longitude": 0,
-    "zoom": 0
-  },
-  "layerTree": [
-    "a0044fd7-f167-445f-b3d1-620a8f94b498",
-    {
-      "name": "level 1 group",
-      "layers": [
-        "2467576f-b527-4cb7-998d-fa1d056fb8a1",
-        {
-          "name": "level 2 group",
-          "layers": [
-            "57ef55ef-facb-48a2-ae1d-c9c824be3e8a"
-          ]
-        }
-      ]
     }
-  ]
-}
+  }
+}
\ No newline at end of file
diff --git a/python/jupytergis_core/jupytergis_core/jgis_ydoc.py b/python/jupytergis_core/jupytergis_core/jgis_ydoc.py
index ad7c002d..2843e045 100644
--- a/python/jupytergis_core/jupytergis_core/jgis_ydoc.py
+++ b/python/jupytergis_core/jupytergis_core/jgis_ydoc.py
@@ -29,6 +29,7 @@ def get(self) -> str:
         layers_tree = self._ylayerTree.to_py()
         return json.dumps(
             dict(layers=layers, sources=sources, options=options, layerTree=layers_tree),
+            sort_keys=True,
             indent=2,
         )
 
diff --git a/ui-tests/tests/left-panel.spec.ts-snapshots/top-layer-hidden-linux.png b/ui-tests/tests/left-panel.spec.ts-snapshots/top-layer-hidden-linux.png
index b9bc0910..b786e3f0 100644
Binary files a/ui-tests/tests/left-panel.spec.ts-snapshots/top-layer-hidden-linux.png and b/ui-tests/tests/left-panel.spec.ts-snapshots/top-layer-hidden-linux.png differ
diff --git a/ui-tests/tests/left-panel.spec.ts-snapshots/top-layer-not-hidden-linux.png b/ui-tests/tests/left-panel.spec.ts-snapshots/top-layer-not-hidden-linux.png
index 1afd85db..d63ad9fd 100644
Binary files a/ui-tests/tests/left-panel.spec.ts-snapshots/top-layer-not-hidden-linux.png and b/ui-tests/tests/left-panel.spec.ts-snapshots/top-layer-not-hidden-linux.png differ
diff --git a/ui-tests/tests/ui.spec.ts-snapshots/Render-test-jGIS-linux.png b/ui-tests/tests/ui.spec.ts-snapshots/Render-test-jGIS-linux.png
index 24575f30..257894aa 100644
Binary files a/ui-tests/tests/ui.spec.ts-snapshots/Render-test-jGIS-linux.png and b/ui-tests/tests/ui.spec.ts-snapshots/Render-test-jGIS-linux.png differ