diff --git a/pyzebra/app/panel_hdf_viewer.py b/pyzebra/app/panel_hdf_viewer.py
index 2492582..6e56b19 100644
--- a/pyzebra/app/panel_hdf_viewer.py
+++ b/pyzebra/app/panel_hdf_viewer.py
@@ -30,6 +30,8 @@ from bokeh.models import (
     Rect,
     ResetTool,
     Select,
+    Slider,
+    Spacer,
     Spinner,
     TableColumn,
     TextAreaInput,
@@ -76,7 +78,7 @@ def create():
 
     def update_image(index=None):
         if index is None:
-            index = index_spinner.value
+            index = index_slider.value
 
         current_image = det_data["data"][index]
         proj_v_line_source.data.update(
@@ -173,8 +175,8 @@ def create():
 
         det_data = pyzebra.read_detector_data(new[0])
 
-        index_spinner.value = 0
-        index_spinner.high = det_data["data"].shape[0] - 1
+        index_slider.value = 0
+        index_slider.end = det_data["data"].shape[0] - 1
 
         zebra_mode = det_data["zebra_mode"]
         if zebra_mode == "nb":
@@ -188,11 +190,11 @@ def create():
     file_select = MultiSelect(title="Available .hdf files:", width=210, height=250)
     file_select.on_change("value", file_select_callback)
 
-    def index_spinner_callback(_attr, _old, new):
+    def index_slider_callback(_attr, _old, new):
         update_image(new)
 
-    index_spinner = Spinner(title="Image index:", value=0, low=0, width=80)
-    index_spinner.on_change("value", index_spinner_callback)
+    index_slider = Slider(title="Image index", value=0, start=0, end=1, width=300)
+    index_slider.on_change("value_throttled", index_slider_callback)
 
     plot = Plot(
         x_range=Range1d(0, IMAGE_W, bounds=(0, IMAGE_W)),
@@ -543,7 +545,7 @@ def create():
     proj_display_min_spinner.on_change("value", proj_display_min_spinner_callback)
 
     def hkl_button_callback():
-        index = index_spinner.value
+        index = index_slider.value
         h, k, l = calculate_hkl(det_data, index)
         image_source.data.update(h=[h], k=[k], l=[l])
 
@@ -601,7 +603,9 @@ def create():
     )
 
     layout_controls = row(
-        column(selection_button, selection_list), column(metadata_table, index_spinner, hkl_button),
+        column(selection_button, selection_list),
+        Spacer(width=20),
+        column(index_slider, metadata_table, hkl_button),
     )
 
     layout_overview = column(