diff --git a/service-worker.js b/service-worker.js
new file mode 100644
index 0000000..d0424a8
--- /dev/null
+++ b/service-worker.js
@@ -0,0 +1,31 @@
+const CACHE_NAME = "woordjes-v1";
+
+const FILES = [
+    "/learn.php",
+    "/assets/css/style.css",
+    "/assets/js/app.js"
+];
+
+self.addEventListener("install", (event) => {
+    event.waitUntil(
+        caches.open(CACHE_NAME).then((cache) => {
+            return cache.addAll(FILES);
+        })
+    );
+});
+
+self.addEventListener("fetch", (event) => {
+
+    const url = event.request.url;
+
+    // API NIET cachen (anders breekt je SRS)
+    if (url.includes("/api/")) {
+        return;
+    }
+
+    event.respondWith(
+        caches.match(event.request).then((cached) => {
+            return cached || fetch(event.request);
+        })
+    );
+});
\ No newline at end of file