diff --git a/api/onnx_web/server/context.py b/api/onnx_web/server/context.py
index 9ab4494b..034fc3c6 100644
--- a/api/onnx_web/server/context.py
+++ b/api/onnx_web/server/context.py
@@ -106,19 +106,19 @@ class ServerContext:
             model_path=environ.get("ONNX_WEB_MODEL_PATH", path.join("..", "models")),
             output_path=environ.get("ONNX_WEB_OUTPUT_PATH", path.join("..", "outputs")),
             params_path=environ.get("ONNX_WEB_PARAMS_PATH", "."),
-            cors_origin=get_list(environ, "ONNX_WEB_CORS_ORIGIN", "*"),
+            cors_origin=get_list(environ, "ONNX_WEB_CORS_ORIGIN", default="*"),
             any_platform=get_boolean(
                 environ, "ONNX_WEB_ANY_PLATFORM", DEFAULT_ANY_PLATFORM
             ),
-            block_platforms=get_list(environ, "ONNX_WEB_BLOCK_PLATFORMS", ""),
+            block_platforms=get_list(environ, "ONNX_WEB_BLOCK_PLATFORMS"),
             default_platform=environ.get("ONNX_WEB_DEFAULT_PLATFORM", None),
             image_format=environ.get("ONNX_WEB_IMAGE_FORMAT", DEFAULT_IMAGE_FORMAT),
             cache_limit=int(environ.get("ONNX_WEB_CACHE_MODELS", DEFAULT_CACHE_LIMIT)),
             show_progress=get_boolean(
                 environ, "ONNX_WEB_SHOW_PROGRESS", DEFAULT_SHOW_PROGRESS
             ),
-            optimizations=get_list(environ, "ONNX_WEB_OPTIMIZATIONS", ""),
-            extra_models=get_list(environ, "ONNX_WEB_EXTRA_MODELS", ""),
+            optimizations=get_list(environ, "ONNX_WEB_OPTIMIZATIONS"),
+            extra_models=get_list(environ, "ONNX_WEB_EXTRA_MODELS"),
             job_limit=int(environ.get("ONNX_WEB_JOB_LIMIT", DEFAULT_JOB_LIMIT)),
             memory_limit=memory_limit,
             admin_token=environ.get("ONNX_WEB_ADMIN_TOKEN", None),
@@ -128,7 +128,7 @@ class ServerContext:
             worker_retries=int(
                 environ.get("ONNX_WEB_WORKER_RETRIES", DEFAULT_WORKER_RETRIES)
             ),
-            feature_flags=get_list(environ, "ONNX_WEB_FEATURE_FLAGS", ""),
+            feature_flags=get_list(environ, "ONNX_WEB_FEATURE_FLAGS"),
             plugins=get_list(environ, "ONNX_WEB_PLUGINS", ""),
             debug=get_boolean(environ, "ONNX_WEB_DEBUG", False),
         )
diff --git a/api/onnx_web/utils.py b/api/onnx_web/utils.py
index 799e9dd5..9dac0d40 100644
--- a/api/onnx_web/utils.py
+++ b/api/onnx_web/utils.py
@@ -41,8 +41,8 @@ def get_boolean(args: Any, key: str, default_value: bool) -> bool:
     return val.lower() in ("1", "t", "true", "y", "yes")
 
 
-def get_list(args: Any, key: str) -> List[str]:
-    return split_list(args.get(key, ""))
+def get_list(args: Any, key: str, default = "") -> List[str]:
+    return split_list(args.get(key, default))
 
 
 def get_and_clamp_float(