diff --git a/frontend/src/components/dev/DevTools.tsx b/frontend/src/components/dev/DevTools.tsx
index 1fa1302..eecceaa 100644
--- a/frontend/src/components/dev/DevTools.tsx
+++ b/frontend/src/components/dev/DevTools.tsx
@@ -28,8 +28,9 @@ export function DevTools() {
     const [isLoading, setIsLoading] = useState<string | null>(null);
     const [error, setError] = useState<string | null>(null);
 
-    // Only show in development or when explicitly enabled
-    const isDev = import.meta.env.DEV || import.meta.env.VITE_DEV_TOOLS === 'true';
+    // Show in development, when explicitly enabled, or on testing domains (*.runfoo.run)
+    const isTestingDomain = typeof window !== 'undefined' && window.location.hostname.endsWith('runfoo.run');
+    const isDev = import.meta.env.DEV || import.meta.env.VITE_DEV_TOOLS === 'true' || isTestingDomain;
     if (!isDev) return null;
 
     const handleQuickLogin = async (devUser: DevUser) => {
@@ -115,8 +116,8 @@ export function DevTools() {
                                     onClick={() => handleQuickLogin(devUser)}
                                     disabled={isLoading !== null}
                                     className={`w-full flex items-center gap-3 p-2 rounded-lg text-left transition-all ${user?.email === devUser.email
-                                            ? 'bg-emerald-50 dark:bg-emerald-900/20 border-2 border-emerald-500'
-                                            : 'bg-slate-50 dark:bg-slate-700/50 hover:bg-slate-100 dark:hover:bg-slate-700 border-2 border-transparent'
+                                        ? 'bg-emerald-50 dark:bg-emerald-900/20 border-2 border-emerald-500'
+                                        : 'bg-slate-50 dark:bg-slate-700/50 hover:bg-slate-100 dark:hover:bg-slate-700 border-2 border-transparent'
                                         } ${isLoading === devUser.email ? 'opacity-50' : ''}`}
                                 >
                                     <div className={`w-8 h-8 rounded-full ${devUser.color} flex items-center justify-center text-white text-xs font-bold`}>