diff --git a/main.py b/main.py
index 73518ca..2507472 100644
--- a/main.py
+++ b/main.py
@@ -1,4 +1,5 @@
 import os
+import multiprocessing
 from flask import Flask, request, render_template
 from timelapse import process_faces
 
@@ -9,28 +10,33 @@ API_KEY = os.environ.get("IMMICH_API_KEY", "")
 BASE_URL = os.environ.get("IMMICH_BASE_URL", "")
 OUTPUT_FOLDER = os.environ.get("OUTPUT_FOLDER", "output")
 
-# model paths
+# Model paths
 FACE_DETECT_MODEL = "mmod_human_face_detector.dat"
 LANDMARK_MODEL = "shape_predictor_68_face_landmarks.dat"
 
+LEFT_EYE_POS = (0.35, 0.45)
+AVAILABLE_CORES = multiprocessing.cpu_count()
 
 @app.route("/", methods=["GET", "POST"])
 def index():
     result = None
     error = None
+    # Create max_workers_options as a list of numbers from 1 to AVAILABLE_CORES
+    max_workers_options = list(range(1, AVAILABLE_CORES + 1))
     if request.method == "POST":
         try:
+            # Read critical parameters from environment variables
             api_key = API_KEY
             base_url = BASE_URL
             output_folder = OUTPUT_FOLDER
+
+            # Get user input from the form
             person_id = request.form["person_id"]
             padding_percent = float(request.form.get("padding_percent", 0.3))
             resize_size = int(request.form.get("resize_size", 512))
             face_resolution_threshold = int(request.form.get("face_resolution_threshold", 128))
             pose_threshold = float(request.form.get("pose_threshold", 25))
-            desired_left_eye_x = float(request.form.get("desired_left_eye_x", 0.35))
-            desired_left_eye_y = float(request.form.get("desired_left_eye_y", 0.45))
-            max_workers = int(request.form.get("max_workers", 4))
+            max_workers = int(request.form.get("max_workers", 1))  # default is 1
 
             processed_files = process_faces(
                 api_key=api_key,
@@ -43,7 +49,7 @@ def index():
                 min_face_width=face_resolution_threshold,
                 min_face_height=face_resolution_threshold,
                 pose_threshold=pose_threshold,
-                desired_left_eye=(desired_left_eye_x, desired_left_eye_y),
+                desired_left_eye=LEFT_EYE_POS,
                 max_workers=max_workers,
                 face_detect_model_path=FACE_DETECT_MODEL,
                 landmark_model_path=LANDMARK_MODEL
@@ -51,8 +57,7 @@ def index():
             result = f"Finished processing. {len(processed_files)} images saved in '{output_folder}'."
         except Exception as e:
             error = f"Error processing request: {e}"
-    return render_template("index.html", result=result, error=error)
-
+    return render_template("index.html", result=result, error=error, max_workers_options=max_workers_options)
 
 if __name__ == "__main__":
     app.run(host="0.0.0.0", port=5000)
diff --git a/templates/index.html b/templates/index.html
index b206aad..2e1f898 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -31,7 +31,8 @@
             color: #555;
         }
         input[type="text"],
-        input[type="number"] {
+        input[type="number"],
+        select {
             width: calc(100% - 20px);
             padding: 8px 10px;
             margin-top: 4px;
@@ -39,16 +40,6 @@
             border-radius: 4px;
             font-size: 14px;
         }
-        details {
-            background: #eef;
-            padding: 10px;
-            margin: 20px 0;
-            border-radius: 4px;
-        }
-        summary {
-            font-weight: bold;
-            cursor: pointer;
-        }
         button {
             background: #28a745;
             color: #fff;
@@ -103,21 +94,14 @@
                 Pose Threshold:
                 <input type="number" step="0.1" name="pose_threshold" value="{{ request.form.pose_threshold or 25 }}">
             </label>
-            <details>
-                <summary>Advanced Options</summary>
-                <label>
-                    Desired Left Eye X:
-                    <input type="number" step="0.01" name="desired_left_eye_x" value="{{ request.form.desired_left_eye_x or 0.35 }}">
-                </label>
-                <label>
-                    Desired Left Eye Y:
-                    <input type="number" step="0.01" name="desired_left_eye_y" value="{{ request.form.desired_left_eye_y or 0.45 }}">
-                </label>
-                <label>
-                    Max Workers:
-                    <input type="number" name="max_workers" value="{{ request.form.max_workers or 4 }}">
-                </label>
-            </details>
+            <label>
+                Max Workers:
+                <select name="max_workers">
+                    {% for i in max_workers_options %}
+                        <option value="{{ i }}" {% if request.form.max_workers|default('1')|int == i %}selected{% endif %}>{{ i }}</option>
+                    {% endfor %}
+                </select>
+            </label>
             <button type="submit">Generate Timelapse</button>
         </form>
         {% if result %}