diff --git a/karaokatalog/ui/static/model/favorites.js b/karaokatalog/ui/static/model/favorites.js
new file mode 100644
index 0000000..3f6cdb5
--- /dev/null
+++ b/karaokatalog/ui/static/model/favorites.js
@@ -0,0 +1,32 @@
+const FAVORITES_STORAGE_KEY = "songAppFavorites"
+
+let favoriteIds = null
+
+export function getFavoriteIds() {
+    if (favoriteIds === null) {
+        favoriteIds = new Set(
+            JSON.parse(localStorage.getItem(FAVORITES_STORAGE_KEY)) || [],
+        )
+    }
+
+    return favoriteIds
+}
+
+function setFavoriteIds(favs) {
+    localStorage.setItem(
+        FAVORITES_STORAGE_KEY,
+        JSON.stringify(Array.from(favs)),
+    )
+}
+
+export function addFavorite(id) {
+    const favs = getFavoriteIds()
+    favs.add(id)
+    setFavoriteIds(favs)
+}
+
+export function removeFavorite(id) {
+    const favs = getFavoriteIds()
+    favs.delete(id)
+    setFavoriteIds(favs)
+}