diff --git a/nicegui/storage.py b/nicegui/storage.py
index 8e7376728..1456569f0 100644
--- a/nicegui/storage.py
+++ b/nicegui/storage.py
@@ -53,7 +53,8 @@ class Storage:
 
     def __init__(self) -> None:
         self.path = Path(os.environ.get('NICEGUI_STORAGE_PATH', '.nicegui')).resolve()
-        self.max_tab_storage_age = timedelta(days=30).total_seconds()
+        self.max_tab_storage_age: float = timedelta(days=30).total_seconds()
+        """Maximum age in seconds before tab storage is automatically purged. Defaults to 30 days."""
         self._general = RedisPersistentDict()  # PersistentDict(self.path / 'storage-general.json', encoding='utf-8')
         self._users: Dict[str, FilePersistentDict] = {}
         self._tabs: Dict[str, observables.ObservableDict] = {}
diff --git a/website/documentation/content/storage_documentation.py b/website/documentation/content/storage_documentation.py
index 9a29faae1..76574e110 100644
--- a/website/documentation/content/storage_documentation.py
+++ b/website/documentation/content/storage_documentation.py
@@ -132,6 +132,22 @@ def tab_storage():
         ui.button('Reload page', on_click=ui.navigate.reload)
 
 
+@doc.demo('Maximum age of tab storage', '''
+    By default, the tab storage is kept for 30 days.
+    You can change this by setting `app.storage.max_tab_storage_age`.
+''')
+def max_tab_storage_age():
+    from nicegui import app
+    from datetime import timedelta
+    # app.storage.max_tab_storage_age = timedelta(minutes=1).total_seconds()
+    ui.label(f'Tab storage age: {timedelta(minutes=1).total_seconds()} seconds')  # HIDE
+
+    @ui.page('/')
+    def index():
+        # ui.label(f'Tab storage age: {app.storage.tab.age} seconds')
+        pass  # HIDE
+
+
 @doc.demo('Short-term memory', '''
     The goal of `app.storage.client` is to store data only for the duration of the current page visit.
     In difference to data stored in `app.storage.tab`