diff --git a/client/index.html b/client/index.html
index d5f41aa..e0470ab 100644
--- a/client/index.html
+++ b/client/index.html
@@ -1,17 +1,37 @@
 <!doctype html>
-<html lang="en">
+<html lang="de">
   <head>
     <meta charset="UTF-8" />
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="Digitales Yacht-Logbuch mit End-to-End-Verschlüsselung und Passkey-Anmeldung. Reisetage, GPS-Tracks, Crew und Schiffsdaten sicher dokumentieren – auch offline als PWA." />
+    <meta name="keywords" content="Yacht-Logbuch, Schiffstagebuch, Bordlogbuch, Segeln, Passkey, E2E-Verschlüsselung, GPS-Track, maritimes Logbuch" />
+    <meta name="author" content="Markus F.J. Busche" />
+    <meta name="robots" content="index, follow" />
+    <meta name="application-name" content="Kapteins Daagbok" />
+    <link rel="canonical" href="https://kapteins-daagbok.eu/" />
     <meta name="mobile-web-app-capable" content="yes" />
     <meta name="apple-mobile-web-app-capable" content="yes" />
     <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />
     <meta name="apple-mobile-web-app-title" content="Daagbok" />
     <meta name="theme-color" content="#1e293b" />
     <link rel="apple-touch-icon" href="/logo.png" />
+    <meta property="og:type" content="website" />
+    <meta property="og:site_name" content="Kapteins Daagbok" />
+    <meta property="og:title" content="Kapteins Daagbok – Digitales Yacht-Logbuch" />
+    <meta property="og:description" content="Sicheres, E2E-verschlüsseltes Logbuch für Skipper: Reisetage, GPS-Tracks, Crew- und Schiffsdaten – mit Passkey-Anmeldung und Offline-PWA." />
+    <meta property="og:url" content="https://kapteins-daagbok.eu/" />
+    <meta property="og:image" content="https://kapteins-daagbok.eu/logo.png" />
+    <meta property="og:image:alt" content="Kapteins Daagbok Logo" />
+    <meta property="og:locale" content="de_DE" />
+    <meta property="og:locale:alternate" content="en_US" />
+    <meta name="twitter:card" content="summary" />
+    <meta name="twitter:title" content="Kapteins Daagbok – Digitales Yacht-Logbuch" />
+    <meta name="twitter:description" content="Sicheres, E2E-verschlüsseltes Logbuch für Skipper: Reisetage, GPS-Tracks, Crew- und Schiffsdaten – mit Passkey-Anmeldung und Offline-PWA." />
+    <meta name="twitter:image" content="https://kapteins-daagbok.eu/logo.png" />
+    <meta name="twitter:image:alt" content="Kapteins Daagbok Logo" />
     <script defer data-domain="kapteins-daagbok.eu" src="https://plausible.elpatron.me/js/script.tagged-events.js"></script>
-    <title>Kapteins Daagbok</title>
+    <title>Kapteins Daagbok – Digitales Yacht-Logbuch</title>
   </head>
   <body>
     <div id="root"></div>
