diff --git a/sw.js b/sw.js
new file mode 100644
index 0000000..e85574e
--- /dev/null
+++ b/sw.js
@@ -0,0 +1,38 @@
+const CACHE_NAME = 'studysphere-v1';
+const ASSETS = [
+  '/',
+  '/index.html',
+  '/css/style.css',
+  '/css/pages.css',
+  '/js/db.js',
+  '/js/ui.js',
+  '/js/pages.js',
+  '/assets/favicon.svg',
+  'https://unpkg.com/lucide@latest',
+  'https://cdn.jsdelivr.net/npm/marked/marked.min.js'
+];
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then((cache) => cache.addAll(ASSETS))
+  );
+});
+
+self.addEventListener('fetch', (event) => {
+  event.respondWith(
+    caches.match(event.request).then((response) => response || fetch(event.request))
+  );
+});
+
+self.addEventListener('activate', (event) => {
+  const cacheWhitelist = [CACHE_NAME];
+  event.waitUntil(
+    caches.keys().then((cacheNames) => {
+      return Promise.all(
+        cacheNames.map((cacheName) => {
+          if (!cacheWhitelist.includes(cacheName)) return caches.delete(cacheName);
+        })
+      );
+    })
+  );
+});