diff --git a/app.py b/app.py
index 27783ff..d76bdce 100644
--- a/app.py
+++ b/app.py
@@ -284,6 +284,12 @@ def service_worker():
 	# Service Worker muss auf Top-Level liegen
 	log_page_view("service_worker", request.headers.get('User-Agent'))
 	return send_from_directory(Path(__file__).parent / 'static', 'sw.js', mimetype='application/javascript')
+@app.route('/screenshot.png')
+def screenshot_image():
+    """Liefert das OpenGraph/Twitter Vorschaubild aus dem Projektstamm."""
+    log_page_view("screenshot", request.headers.get('User-Agent'))
+    return send_from_directory(Path(__file__).parent, 'screenshot.png', mimetype='image/png')
+
 
 
 @app.route('/login', methods=['GET', 'POST'])
diff --git a/templates/index.html b/templates/index.html
index 9f5b7e3..87a30b4 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -11,9 +11,14 @@
     <meta property="og:title" content="Wordle‑Cheater (DE)" />
     <meta property="og:description" content="Finde deutsche 5‑Buchstaben‑Wörter mit Positions- und Buchstabenfiltern. Quellen: OpenThesaurus & wordfreq." />
     <meta property="og:url" content="{{ request.url_root }}" />
+    <meta property="og:site_name" content="Wordle‑Cheater (DE)" />
+    <meta property="og:locale" content="de_DE" />
+    <meta property="og:image" content="{{ url_for('screenshot_image', _external=True) }}" />
     <meta name="twitter:card" content="summary" />
     <meta name="twitter:title" content="Wordle‑Cheater (DE)" />
     <meta name="twitter:description" content="Finde deutsche 5‑Buchstaben‑Wörter mit Positions- und Buchstabenfiltern. Quellen: OpenThesaurus & wordfreq." />
+    <meta name="twitter:image" content="{{ url_for('screenshot_image', _external=True) }}" />
+    <link rel="alternate" hreflang="de" href="{{ request.url_root }}" />
     <link rel="icon" type="image/svg+xml" href="{{ url_for('static', filename='favicon.svg') }}" />
     <link rel="manifest" href="/manifest.webmanifest" />
     <meta name="theme-color" content="#0b1220" />
@@ -28,6 +33,19 @@
             } catch (e) {}
         })();
     </script>
+    <script type="application/ld+json">
+    {
+      "@context": "https://schema.org",
+      "@type": "WebApplication",
+      "name": "Wordle‑Cheater (DE)",
+      "url": "{{ request.url_root }}",
+      "applicationCategory": "UtilitiesApplication",
+      "operatingSystem": "Web",
+      "description": "Finde deutsche 5‑Buchstaben‑Wörter anhand bekannter Buchstaben und Positionen. Quellen: OpenThesaurus & wordfreq.",
+      "inLanguage": "de",
+      "offers": { "@type": "Offer", "price": "0", "priceCurrency": "EUR" }
+    }
+    </script>
     <style>
         :root { --bg:#ffffff; --text:#111827; --muted:#6b7280; --badge-bg:#e5e7eb; --badge-text:#111827; --border:#e5e7eb; --skip-bg:#111827; --skip-text:#ffffff; --button-bg:#111827; --button-text:#ffffff; --input-bg:#ffffff; --input-text:#111827; --error:#b91c1c; }
         [data-theme="dark"] { --bg:#0b1220; --text:#e5e7eb; --muted:#9ca3af; --badge-bg:#374151; --badge-text:#f9fafb; --border:#334155; --skip-bg:#e5e7eb; --skip-text:#111827; --button-bg:#e5e7eb; --button-text:#111827; --input-bg:#111827; --input-text:#e5e7eb; --error:#ef4444; }