diff --git a/src/serviceworker/mod.ts b/src/serviceworker/mod.ts
index 0df7955..ec44acb 100644
--- a/src/serviceworker/mod.ts
+++ b/src/serviceworker/mod.ts
@@ -84,8 +84,9 @@ if (IS_SW) {
 		event.waitUntil(openPreCache())
 	})
 
-	self.addEventListener('activate', () => {
-		//TODO handle activation
+	self.addEventListener('activate', (event) => {
+		// Clear old caches to reduce storage usage
+		event.waitUntil(clearOldCaches())
 	})
 
 	self.addEventListener('fetch', (event) => {
@@ -252,6 +253,23 @@ async function openPreCache() {
 	return { cache, version, preCachedUrls }
 }
 
+async function clearOldCaches() {
+	// Clear memory
+	memory.clear()
+
+	// List all caches by their names.
+	const names = await caches.keys()
+	const preCacheName = await swStorage.getItem('$sw.pre-cache.version')
+	const dynCacheName = await swStorage.getItem('$sw.dyn-cache.version')
+
+	for (const name of names) {
+		// If a cache's name is the current name, delete it.
+		if (name === preCacheName) continue
+		if (name == dynCacheName) continue
+		caches.delete(name)
+	}
+}
+
 export function main() {
 	console.assert()
 }