diff --git a/src/features/onboarding/components/onboarding-form.tsx b/src/features/onboarding/components/onboarding-form.tsx
index 081879e..47395da 100644
--- a/src/features/onboarding/components/onboarding-form.tsx
+++ b/src/features/onboarding/components/onboarding-form.tsx
@@ -17,8 +17,19 @@ function detectPlatform(): "ios" | "android" | "unknown" {
 	return "unknown";
 }
 
+export function isInstalledPwa(): boolean {
+	if (window.matchMedia("(display-mode: standalone)").matches) return true;
+	if (
+		"standalone" in navigator &&
+		(navigator as { standalone?: boolean }).standalone
+	)
+		return true;
+	return false;
+}
+
 export function OnboardingForm() {
 	const navigate = useNavigate();
+	const installed = useMemo(() => isInstalledPwa(), []);
 	const [step, setStep] = useState(0);
 	const [dbReady, setDbReady] = useState(false);
 	const [submitting, setSubmitting] = useState(false);
@@ -55,8 +66,8 @@ export function OnboardingForm() {
 		<div className="flex min-h-[80vh] flex-col items-center justify-center">
 			<div className="w-full max-w-md space-y-6">
 				{step === 0 && <IntroScreen />}
-				{step === 1 && <InstallScreen />}
-				{step === 2 && (
+				{!installed && step === 1 && <InstallScreen />}
+				{step === (installed ? 1 : 2) && (
 					<>
 						<div className="space-y-2 text-center">
 							<h1 className="text-2xl font-bold">Über dich</h1>
@@ -167,13 +178,13 @@ export function OnboardingForm() {
 					</>
 				)}
 
-				{step < 2 && (
+				{step < (installed ? 1 : 2) && (
 					<Button className="w-full" onClick={() => setStep(step + 1)}>
 						Weiter
 					</Button>
 				)}
 
-				<DotIndicator current={step} />
+				<DotIndicator current={step} installed={installed} />
 			</div>
 		</div>
 	);
@@ -267,8 +278,16 @@ function InstallScreen() {
 	);
 }
 
-function DotIndicator({ current }: { current: number }) {
-	const dots = ["intro", "install", "form"] as const;
+function DotIndicator({
+	current,
+	installed,
+}: {
+	current: number;
+	installed: boolean;
+}) {
+	const dots = installed
+		? (["intro", "form"] as const)
+		: (["intro", "install", "form"] as const);
 	return (
 		<div className="flex justify-center gap-2">
 			{dots.map((id, i) => (
diff --git a/src/routes/__root.tsx b/src/routes/__root.tsx
index 547a474..099e6e1 100644
--- a/src/routes/__root.tsx
+++ b/src/routes/__root.tsx
@@ -5,6 +5,8 @@ import {
 	useMatchRoute,
 } from "@tanstack/react-router";
 import { ListChecks, Settings, Users } from "lucide-react";
+import { useMemo } from "react";
+import { isInstalledPwa } from "@/features/onboarding/components/onboarding-form";
 
 export const Route = createRootRoute({
 	component: () => {
@@ -12,9 +14,16 @@ export const Route = createRootRoute({
 		const isOnboarding = matchRoute({ to: "/onboarding" });
 		const isRoot = matchRoute({ to: "/" });
 		const hideNav = isOnboarding || isRoot;
+		const installed = useMemo(() => isInstalledPwa(), []);
 
 		return (
 			<div className="flex min-h-screen flex-col bg-background text-foreground">
+				{!hideNav && !installed && (
+					<div className="bg-amber-500 px-4 py-2 text-center text-sm font-medium text-white dark:bg-amber-600">
+						App nicht installiert — füge TherapyFinder zum Home-Bildschirm
+						hinzu, um Datenverlust zu vermeiden.
+					</div>
+				)}
 				<main className="mx-auto w-full max-w-2xl flex-1 px-4 pb-20 pt-6">
 					<Outlet />
 				</main>