diff --git a/api/onnx_web/serve.py b/api/onnx_web/serve.py
index 3a2f35ba..061284cb 100644
--- a/api/onnx_web/serve.py
+++ b/api/onnx_web/serve.py
@@ -256,7 +256,8 @@ def load_platforms():
     global available_platforms
 
     providers = get_available_providers()
-    available_platforms = [p for p in platform_providers if (platform_providers[p] in providers)]
+    available_platforms = [p for p in platform_providers if (
+        platform_providers[p] in providers)]
 
     print('available acceleration platforms: %s' % (available_platforms))
 
@@ -502,6 +503,6 @@ def ready():
     })
 
 
-@app.route('/api/output/<path:filename>')
+@app.route('/output/<path:filename>')
 def output(filename: str):
     return send_from_directory(path.join('..', context.output_path), filename, as_attachment=False)
diff --git a/gui/src/client.ts b/gui/src/client.ts
index f828029d..54bd49fb 100644
--- a/gui/src/client.ts
+++ b/gui/src/client.ts
@@ -393,7 +393,7 @@ export async function parseApiResponse(root: string, res: Response): Promise<Ima
 
   if (res.status === STATUS_SUCCESS) {
     const data = await res.json() as LimitedResponse;
-    const url = makeApiUrl(root, 'output', data.output).toString();
+    const url = new URL(joinPath('output', data.output), root).toString();
     return {
       ...data,
       output: {