diff --git a/assets/js/app.js b/assets/js/app.js
index 860b946..fec4c3c 100644
--- a/assets/js/app.js
+++ b/assets/js/app.js
@@ -55,3 +55,16 @@ liveSocket.connect();
 window.liveSocket = liveSocket;
 
 handleDarkMode();
+
+if ("serviceWorker" in navigator) {
+  // Register a service worker hosted at the root of the
+  // site using the default scope.
+  navigator.serviceWorker
+    .register("/assets/serviceworker.js", { scope: "/" })
+    .then(
+      (registration) => console.log("Service worker registration succeeded."),
+      (error) => console.error(`Service worker registration failed: ${error}`),
+    );
+} else {
+  console.error("Service workers are not supported.");
+}
diff --git a/assets/js/serviceworker.js b/assets/js/serviceworker.js
new file mode 100644
index 0000000..6d4fb15
--- /dev/null
+++ b/assets/js/serviceworker.js
@@ -0,0 +1,69 @@
+"use strict";
+
+const version = "20241231";
+const staticCacheName = "static-" + version;
+const cacheList = [staticCacheName];
+
+async function updateStaticCache() {
+  let staticCache = await caches.open(staticCacheName);
+  staticCache.addAll([
+    "/assets/video.js",
+    "/assets/app.css",
+    "/assets/app.js",
+    "/images/signee.png",
+    "/images/pfeil.png",
+    "/images/avatar.jpg",
+    "/font/noway-regular-webfont.woff",
+    "/font/noway-regular-webfont.woff2",
+    "/font/Virgil.woff2",
+  ]);
+}
+
+async function clearOldCaches() {
+  let keys = await caches.keys();
+  return Promise.all(
+    keys
+      .filter((key) => !cacheList.includes(key))
+      .map((key) => caches.delete(key)),
+  );
+}
+
+addEventListener("install", (installEvent) => {
+  installEvent.waitUntil(updateStaticCache());
+  skipWaiting();
+});
+
+addEventListener("activate", (activateEvent) => {
+  activateEvent.waitUntil(clearOldCaches());
+  clients.claim();
+});
+
+addEventListener("fetch", (fetchEvent) => {
+  let request = fetchEvent.request;
+  let url = new URL(request.url);
+
+  // Only deal with requests to my own server
+  if (url.origin !== location.origin) {
+    return;
+  }
+
+  // Only deal with GET requests
+  if (request.method !== "GET") {
+    return;
+  }
+
+  // For HTML requests, try the preload first, then network, fall back to the cache, finally the offline page
+  if (
+    request.mode === "navigate" ||
+    request.headers.get("Accept").includes("text/html")
+  ) {
+    return;
+  }
+
+  // For non-HTML requests, look in the cache first, fall back to the network
+  fetchEvent.respondWith(
+    caches.match(request).then((responseFromCache) => {
+      return responseFromCache || fetch(request);
+    }),
+  );
+});
diff --git a/config/config.exs b/config/config.exs
index 718fb19..a7ec87f 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -36,7 +36,7 @@ config :bun,
   install: [args: ~w(install), cd: Path.expand("../assets", __DIR__), env: %{}],
   default: [
     args:
-      ~w(build js/app.js js/storybook.js js/video.js --format=iife --outdir=../priv/static/assets --external /fonts/* --external /images/*),
+      ~w(build js/app.js js/storybook.js js/video.js js/serviceworker.js --format=iife --outdir=../priv/static/assets --external /fonts/* --external /images/*),
     cd: Path.expand("../assets", __DIR__),
     env: %{}
   ],
diff --git a/lib/kobrakai_web/components/layouts/root.html.heex b/lib/kobrakai_web/components/layouts/root.html.heex
index 178787c..0529d35 100644
--- a/lib/kobrakai_web/components/layouts/root.html.heex
+++ b/lib/kobrakai_web/components/layouts/root.html.heex
@@ -19,7 +19,13 @@
     <link phx-track-static rel="stylesheet" href={~p"/assets/app.css"} />
     <script defer phx-track-static type="text/javascript" src={~p"/assets/app.js"}>
     </script>
-    <script async phx-track-static type="text/javascript" src={~p"/assets/video.js"}>
+    <script
+      :if={assigns[:video_js]}
+      defer
+      phx-track-static
+      type="text/javascript"
+      src={~p"/assets/video.js"}
+    >
     </script>
 
     <script type="text/javascript">
diff --git a/lib/kobrakai_web/endpoint.ex b/lib/kobrakai_web/endpoint.ex
index 80d3ce8..0cb0396 100644
--- a/lib/kobrakai_web/endpoint.ex
+++ b/lib/kobrakai_web/endpoint.ex
@@ -27,7 +27,8 @@ defmodule KobrakaiWeb.Endpoint do
     gzip: true,
     at: "/",
     from: :kobrakai,
-    only: KobrakaiWeb.static_paths()
+    only: KobrakaiWeb.static_paths(),
+    headers: {__MODULE__, :static_headers, []}
 
   # Code reloading can be explicitly enabled under the
   # :code_reloader configuration of your endpoint.
@@ -68,4 +69,11 @@ defmodule KobrakaiWeb.Endpoint do
     |> Phoenix.Controller.put_router_url(uri)
     |> Phoenix.Controller.put_static_url(uri)
   end
+
+  def static_headers(conn) do
+    case conn.request_path do
+      "/assets/serviceworker.js" -> [{"Service-Worker-Allowed", "/"}]
+      _ -> []
+    end
+  end
 end
diff --git a/lib/kobrakai_web/router.ex b/lib/kobrakai_web/router.ex
index 9290ed4..f6304da 100644
--- a/lib/kobrakai_web/router.ex
+++ b/lib/kobrakai_web/router.ex
@@ -55,7 +55,7 @@ defmodule KobrakaiWeb.Router do
     get "/kolumne/:id", BlogController, :show
 
     get "/videos", VideoController, :index
-    get "/videos/:id", VideoController, :show
+    get "/videos/:id", VideoController, :show, assigns: %{video_js: true}
 
     get "/photography", CustomController, :photography
     get "/werdegang", CustomController, :cv
diff --git a/lib/kobrakai_web/views/page_html/home.html.heex b/lib/kobrakai_web/views/page_html/home.html.heex
index 63ecdaa..be9704c 100644
--- a/lib/kobrakai_web/views/page_html/home.html.heex
+++ b/lib/kobrakai_web/views/page_html/home.html.heex
@@ -11,7 +11,11 @@
         ]}
         href={url(@conn, ~p"/videos/#{video.id}")}
       >
-        <.image class="border-white border-2 mb-1" src={video.thumbnail} size={{640, 0}} />
+        <.image
+          class="border-white border-2 mb-1 aspect-[16/9]"
+          src={video.thumbnail}
+          size={{640, 0}}
+        />
         <div class="text-gray-500 dark:text-gray-400 text-sm">
           {Calendar.strftime(video.date, "%d.%m.%Y")}
         </div>