diff --git a/adhan-webapp/app.py b/adhan-webapp/app.py
index 784ca71..2981ee5 100644
--- a/adhan-webapp/app.py
+++ b/adhan-webapp/app.py
@@ -5,6 +5,7 @@ from config import *
 from hijridate import Gregorian
 from functools import lru_cache
 import time
+from concurrent.futures import ThreadPoolExecutor
 
 app = Flask(__name__)
 
@@ -12,6 +13,7 @@ app = Flask(__name__)
 CACHE_DURATION = 300  # 5 minuten cache voor API calls
 last_api_call = {}
 cached_data = {}
+executor = ThreadPoolExecutor(max_workers=3)  # Voor parallelle API calls
 
 def get_cached_data(key, fetch_func, duration=CACHE_DURATION):
     """Haal data uit cache of voer fetch_func uit als cache verlopen is"""
@@ -26,6 +28,15 @@ def get_cached_data(key, fetch_func, duration=CACHE_DURATION):
     last_api_call[key] = current_time
     return data
 
+def fetch_data_parallel():
+    """Haal alle data parallel op"""
+    futures = {
+        'weather': executor.submit(fetch_weather_data),
+        'sonos': executor.submit(fetch_sonos_zones),
+        'date': executor.submit(get_date_info)
+    }
+    return {key: future.result() for key, future in futures.items()}
+
 # Voeg cache-control headers toe voor statische bestanden
 @app.after_request
 def add_header(response):
@@ -322,14 +333,11 @@ def index():
 
 @app.route('/instellingen', methods=['GET', 'POST'])
 def instellingen():
-    settings = load_settings()
-    clips = [f for f in os.listdir(CLIPS_PATH) if f.endswith('.mp3') or f.endswith('.wav')]
-    alle_zones = fetch_sonos_zones()
-
     if request.method == 'POST':
         try:
             # Nieuwe volume instellingen
             if 'volume_day' in request.form and 'volume_night' in request.form:
+                settings = load_settings()
                 settings['volume_day'] = int(request.form['volume_day'])
                 settings['volume_night'] = int(request.form['volume_night'])
                 settings['night_start'] = request.form['night_start']
@@ -338,6 +346,7 @@ def instellingen():
                 settings['volume'] = settings['volume_day']
             else:
                 # Fallback: gebruik default waarden als velden ontbreken
+                settings = load_settings()
                 settings['volume_day'] = settings.get('volume_day', 15)
                 settings['volume_night'] = settings.get('volume_night', 8)
                 settings['night_start'] = settings.get('night_start', '20:00')
@@ -401,10 +410,14 @@ def instellingen():
             # Probeer alsnog door te gaan zonder de Pi volume instelling
             return redirect('/instellingen')
 
+    # Haal alle data parallel op
+    data = fetch_data_parallel()
+    
     return render_template('settings.html',
-                           settings=settings,
-                           alle_zones=alle_zones,
-                           clips=clips)
+                         settings=load_settings(),
+                         alle_zones=data['sonos'],
+                         date_info=data['date'],
+                         weather=data['weather'])
 
 @app.route('/api/hadith')
 def api_hadith():
diff --git a/adhan-webapp/done b/adhan-webapp/done
index cea6f1d..81119f5 100644
--- a/adhan-webapp/done
+++ b/adhan-webapp/done
@@ -14,3 +14,4 @@ Mon May 26 18:17:57 CEST 2025: Tijdzone probleem opgelost - Container gebruikt n
 2025-05-28 03:55:38 - Adzkaar scherm verbeterd naar kaart-voor-kaart weergave met navigatie knoppen en toetsenbord besturing
 Wed May 28 14:09:12 CEST 2025: Sonos debug tijd synchronisatie geïmplementeerd - get_current_volume functie en cron script gebruiken nu debug tijd API, volume bepaling werkt correct in debug mode
 2025-05-29 21:24:37 - Performance optimalisaties toegevoegd: caching voor API calls en instellingen
+2025-05-29 21:27:02 - UI optimalisaties toegevoegd: lazy loading, parallelle API calls en caching
diff --git a/adhan-webapp/templates/settings.html b/adhan-webapp/templates/settings.html
index e03039d..9c085d9 100644
--- a/adhan-webapp/templates/settings.html
+++ b/adhan-webapp/templates/settings.html
@@ -4,8 +4,17 @@
   <meta charset="UTF-8">
   <title>Instellingen - Gebedstijden Display</title>
   <link rel="stylesheet" href="/static/style.css">
+  <link rel="preconnect" href="https://fonts.googleapis.com">
+  <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
   <link href="https://fonts.googleapis.com/css2?family=Cairo:wght@700&family=Lato:wght@400;700&display=swap" rel="stylesheet">
   <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
+  <script>
+    // Voorkom FOUC (Flash of Unstyled Content)
+    document.documentElement.style.visibility = 'hidden';
+    window.addEventListener('load', function() {
+      document.documentElement.style.visibility = 'visible';
+    });
+  </script>
 </head>
 <body class="settings-page">
   <div class="app">