diff --git a/spikeinterface_gui/backend_panel.py b/spikeinterface_gui/backend_panel.py
index dd44111..2704a87 100644
--- a/spikeinterface_gui/backend_panel.py
+++ b/spikeinterface_gui/backend_panel.py
@@ -185,10 +185,9 @@ def listen_setting_changes(view):
 
 class PanelMainWindow:
 
-    def __init__(self, controller, layout_preset=None, layout=None, user_settings=None):
+    def __init__(self, controller, layout_dict=None, user_settings=None):
         self.controller = controller
-        self.layout_preset = layout_preset
-        self.layout = layout
+        self.layout_dict = layout_dict
         self.verbose = controller.verbose
 
         self.make_views(user_settings)
@@ -258,7 +257,7 @@ def create_main_layout(self):
 
         pn.extension("gridstack")
 
-        preset = get_layout_description(self.layout_preset, self.layout)
+        preset = self.layout_dict
 
         layout_zone = {}
         for zone, view_names in preset.items():
diff --git a/spikeinterface_gui/backend_qt.py b/spikeinterface_gui/backend_qt.py
index 56ca7ab..036c4d1 100644
--- a/spikeinterface_gui/backend_qt.py
+++ b/spikeinterface_gui/backend_qt.py
@@ -141,13 +141,12 @@ def stop_listen_setting_changes(view):
 class QtMainWindow(QT.QMainWindow):
     main_window_closed = QT.pyqtSignal(object)
 
-    def __init__(self, controller, parent=None, layout_preset=None, layout=None, user_settings=None):
+    def __init__(self, controller, parent=None, layout_dict=None, user_settings=None):
         QT.QMainWindow.__init__(self, parent)
         
         self.controller = controller
         self.verbose = controller.verbose
-        self.layout_preset = layout_preset
-        self.layout = layout
+        self.layout_dict = layout_dict
         
         self.make_views(user_settings)
         self.create_main_layout()
@@ -206,7 +205,7 @@ def create_main_layout(self):
 
         self.setDockNestingEnabled(True)
 
-        preset = get_layout_description(self.layout_preset, self.layout)
+        preset = self.layout_dict
 
         widgets_zone = {}
         for zone, view_names in preset.items():
diff --git a/spikeinterface_gui/layout_presets.py b/spikeinterface_gui/layout_presets.py
index c9a4c71..96812f5 100644
--- a/spikeinterface_gui/layout_presets.py
+++ b/spikeinterface_gui/layout_presets.py
@@ -34,7 +34,7 @@ def _check_valid_layout_dict(layout_dict):
             list_of_possible_class_views = list(possible_class_views.keys())
             if class_view not in list_of_possible_class_views:
                 raise KeyError(f"View '{class_view}' in layout dictionary not equal to a valid View. "\
-                                "Valid views are {list_of_possible_class_views}")
+                                f"Valid views are {list_of_possible_class_views}")
 
 def get_layout_description(preset_name, layout=None):
     if isinstance(layout, dict):
diff --git a/spikeinterface_gui/main.py b/spikeinterface_gui/main.py
index 0e8545f..42fee34 100644
--- a/spikeinterface_gui/main.py
+++ b/spikeinterface_gui/main.py
@@ -7,11 +7,13 @@
 
 from spikeinterface import load_sorting_analyzer, load
 from spikeinterface.core.core_tools import is_path_remote
+from spikeinterface.core.sortinganalyzer import get_available_analyzer_extensions
 from .utils_global import get_config_folder
+from spikeinterface_gui.layout_presets import get_layout_description
 
 import spikeinterface_gui
 from spikeinterface_gui.controller import Controller
-
+from spikeinterface_gui.viewlist import possible_class_views
 
 def run_mainwindow(
     analyzer,
@@ -121,6 +123,11 @@ def run_mainwindow(
     if verbose:
         import time
         t0 = time.perf_counter()
+
+    layout_dict = get_layout_description(layout_preset, layout)
+    if skip_extensions is None:
+        skip_extensions = find_skippable_extensions(layout_dict)
+
     controller = Controller(
         analyzer, backend=backend, verbose=verbose,
         curation=curation, curation_data=curation_dict,
@@ -146,7 +153,7 @@ def run_mainwindow(
 
         app = mkQApp()
 
-        win = QtMainWindow(controller, layout_preset=layout_preset, layout=layout, user_settings=user_settings)
+        win = QtMainWindow(controller, layout_dict=layout_dict, user_settings=user_settings)
         win.setWindowTitle('SpikeInterface GUI')
         # Set window icon
         icon_file = Path(__file__).absolute().parent / 'img' / 'si.png'
@@ -158,7 +165,7 @@ def run_mainwindow(
     
     elif backend == "panel":
         from .backend_panel import PanelMainWindow, start_server
-        win = PanelMainWindow(controller, layout_preset=layout_preset, layout=layout, user_settings=user_settings)
+        win = PanelMainWindow(controller, layout_dict=layout_dict, user_settings=user_settings)
 
         if start_app or panel_window_servable:
             win.main_layout.servable(title='SpikeInterface GUI')
@@ -349,3 +356,25 @@ def run_mainwindow_cli():
             disable_save_settings_button=disable_save_settings_button,
         )
 
+def find_skippable_extensions(layout_dict):
+    """
+    Returns the extensions which don't need to be loaded, depending on which views the user
+    wants to load. Does this by taking all possible extensions, then removing any which are
+    needed by a view.
+    """
+    
+    all_extensions = set(get_available_analyzer_extensions())
+
+    view_per_zone = list(layout_dict.values())
+    list_of_views = [view for zone_views in view_per_zone for view in zone_views]
+
+    needed_extensions = ['unit_locations']
+
+    for view in list_of_views:
+        extensions_view_depend_on = possible_class_views[view]._depend_on
+        if extensions_view_depend_on is not None:
+            needed_extensions += extensions_view_depend_on
+
+    skippable_extensions = list(all_extensions.difference(set(needed_extensions)))
+
+    return skippable_extensions
\ No newline at end of file