diff --git a/_locales/de/messages.json b/_locales/de/messages.json
new file mode 100644
index 0000000..554f4ac
--- /dev/null
+++ b/_locales/de/messages.json
@@ -0,0 +1,28 @@
+{
+  "extensionName": {
+    "message": "NotebookLM Filter"
+  },
+  "extensionDescription": {
+    "message": "Eine einfache NotebookLM-Filtererweiterung",
+    "description": "Description of the extension"
+  },
+  "extensionTitle": {
+    "message": "NotebookLM Filter"
+  },
+  "addFilterButton": {
+    "message": "Neuen Filter hinzufügen",
+    "description": "Button to add a new filter"
+  },
+  "backButton": {
+    "message": "←",
+    "description": "Back button symbol"
+  },
+  "filterInputPlaceholder": {
+    "message": "Filterschlüsselwort eingeben...",
+    "description": "Placeholder text for filter input field"
+  },
+  "confirmButton": {
+    "message": "Bestätigen",
+    "description": "Button to confirm adding a filter"
+  }
+}
diff --git a/_locales/en/messages.json b/_locales/en/messages.json
new file mode 100644
index 0000000..acd8e05
--- /dev/null
+++ b/_locales/en/messages.json
@@ -0,0 +1,28 @@
+{
+  "extensionName": {
+    "message": "NotebookLM Filter"
+  },
+  "extensionDescription": {
+    "message": "A simple NotebookLM filtering extension",
+    "description": "Description of the extension"
+  },
+  "extensionTitle": {
+    "message": "NotebookLM Filter"
+  },
+  "addFilterButton": {
+    "message": "Add New Filter",
+    "description": "Button to add a new filter"
+  },
+  "backButton": {
+    "message": "←",
+    "description": "Back button symbol"
+  },
+  "filterInputPlaceholder": {
+    "message": "Enter filter keyword...",
+    "description": "Placeholder text for filter input field"
+  },
+  "confirmButton": {
+    "message": "Confirm",
+    "description": "Button to confirm adding a filter"
+  }
+}
diff --git a/_locales/es/messages.json b/_locales/es/messages.json
new file mode 100644
index 0000000..ac68632
--- /dev/null
+++ b/_locales/es/messages.json
@@ -0,0 +1,28 @@
+{
+  "extensionName": {
+    "message": "NotebookLM Filter"
+  },
+  "extensionDescription": {
+    "message": "Una extensión simple de filtrado de NotebookLM",
+    "description": "Description of the extension"
+  },
+  "extensionTitle": {
+    "message": "NotebookLM Filter"
+  },
+  "addFilterButton": {
+    "message": "Agregar Nuevo Filtro",
+    "description": "Button to add a new filter"
+  },
+  "backButton": {
+    "message": "←",
+    "description": "Back button symbol"
+  },
+  "filterInputPlaceholder": {
+    "message": "Ingrese la palabra clave del filtro...",
+    "description": "Placeholder text for filter input field"
+  },
+  "confirmButton": {
+    "message": "Confirmar",
+    "description": "Button to confirm adding a filter"
+  }
+}
diff --git a/_locales/fr/messages.json b/_locales/fr/messages.json
new file mode 100644
index 0000000..ab6f50e
--- /dev/null
+++ b/_locales/fr/messages.json
@@ -0,0 +1,28 @@
+{
+  "extensionName": {
+    "message": "NotebookLM Filter"
+  },
+  "extensionDescription": {
+    "message": "Une extension simple de filtrage NotebookLM",
+    "description": "Description of the extension"
+  },
+  "extensionTitle": {
+    "message": "NotebookLM Filter"
+  },
+  "addFilterButton": {
+    "message": "Ajouter un Nouveau Filtre",
+    "description": "Button to add a new filter"
+  },
+  "backButton": {
+    "message": "←",
+    "description": "Back button symbol"
+  },
+  "filterInputPlaceholder": {
+    "message": "Entrez le mot-clé du filtre...",
+    "description": "Placeholder text for filter input field"
+  },
+  "confirmButton": {
+    "message": "Confirmer",
+    "description": "Button to confirm adding a filter"
+  }
+}
diff --git a/_locales/hi/messages.json b/_locales/hi/messages.json
new file mode 100644
index 0000000..412f7d3
--- /dev/null
+++ b/_locales/hi/messages.json
@@ -0,0 +1,28 @@
+{
+  "extensionName": {
+    "message": "NotebookLM Filter"
+  },
+  "extensionDescription": {
+    "message": "एक सरल NotebookLM फ़िल्टरिंग एक्सटेंशन",
+    "description": "Description of the extension"
+  },
+  "extensionTitle": {
+    "message": "NotebookLM Filter"
+  },
+  "addFilterButton": {
+    "message": "नया फ़िल्टर जोड़ें",
+    "description": "Button to add a new filter"
+  },
+  "backButton": {
+    "message": "←",
+    "description": "Back button symbol"
+  },
+  "filterInputPlaceholder": {
+    "message": "फ़िल्टर कीवर्ड दर्ज करें...",
+    "description": "Placeholder text for filter input field"
+  },
+  "confirmButton": {
+    "message": "पुष्टि करें",
+    "description": "Button to confirm adding a filter"
+  }
+}
diff --git a/_locales/ja/messages.json b/_locales/ja/messages.json
new file mode 100644
index 0000000..bfb013c
--- /dev/null
+++ b/_locales/ja/messages.json
@@ -0,0 +1,28 @@
+{
+  "extensionName": {
+    "message": "NotebookLM Filter"
+  },
+  "extensionDescription": {
+    "message": "シンプルな NotebookLM フィルタリング拡張機能",
+    "description": "Description of the extension"
+  },
+  "extensionTitle": {
+    "message": "NotebookLM Filter"
+  },
+  "addFilterButton": {
+    "message": "新しいフィルターを追加",
+    "description": "Button to add a new filter"
+  },
+  "backButton": {
+    "message": "←",
+    "description": "Back button symbol"
+  },
+  "filterInputPlaceholder": {
+    "message": "フィルターキーワードを入力...",
+    "description": "Placeholder text for filter input field"
+  },
+  "confirmButton": {
+    "message": "確認",
+    "description": "Button to confirm adding a filter"
+  }
+}
diff --git a/_locales/pt_BR/messages.json b/_locales/pt_BR/messages.json
new file mode 100644
index 0000000..b220b9c
--- /dev/null
+++ b/_locales/pt_BR/messages.json
@@ -0,0 +1,28 @@
+{
+  "extensionName": {
+    "message": "NotebookLM Filter"
+  },
+  "extensionDescription": {
+    "message": "Uma simples extensão de filtragem do NotebookLM",
+    "description": "Description of the extension"
+  },
+  "extensionTitle": {
+    "message": "NotebookLM Filter"
+  },
+  "addFilterButton": {
+    "message": "Adicionar Novo Filtro",
+    "description": "Button to add a new filter"
+  },
+  "backButton": {
+    "message": "←",
+    "description": "Back button symbol"
+  },
+  "filterInputPlaceholder": {
+    "message": "Digite a palavra-chave do filtro...",
+    "description": "Placeholder text for filter input field"
+  },
+  "confirmButton": {
+    "message": "Confirmar",
+    "description": "Button to confirm adding a filter"
+  }
+}
diff --git a/_locales/zh_TW/messages.json b/_locales/zh_TW/messages.json
new file mode 100644
index 0000000..ea01c28
--- /dev/null
+++ b/_locales/zh_TW/messages.json
@@ -0,0 +1,28 @@
+{
+  "extensionName": {
+    "message": "NotebookLM Filter"
+  },
+  "extensionDescription": {
+    "message": "簡單的 NotebookLM 篩選擴充功能",
+    "description": "Description of the extension"
+  },
+  "extensionTitle": {
+    "message": "NotebookLM Filter"
+  },
+  "addFilterButton": {
+    "message": "新增篩選器",
+    "description": "Button to add a new filter"
+  },
+  "backButton": {
+    "message": "←",
+    "description": "Back button symbol"
+  },
+  "filterInputPlaceholder": {
+    "message": "輸入篩選關鍵字...",
+    "description": "Placeholder text for filter input field"
+  },
+  "confirmButton": {
+    "message": "確認",
+    "description": "Button to confirm adding a filter"
+  }
+}
diff --git a/manifest.json b/manifest.json
index 90c59f9..5794b46 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,8 +1,9 @@
 {
   "manifest_version": 3,
-  "name": "NotebookLM Filter",
-  "version": "1.2.0",
-  "description": "A simple NotebookLM filtering extension",
+  "name": "__MSG_extensionName__",
+  "version": "1.3.0",
+  "description": "__MSG_extensionDescription__",
+  "default_locale": "en",
   "permissions": ["activeTab", "storage"],
   "content_scripts": [
     {
@@ -13,7 +14,7 @@
   ],
   "action": {
     "default_popup": "popup.html",
-    "default_title": "NotebookLM Filter"
+    "default_title": "__MSG_extensionTitle__"
   },
   "icons": {
     "16": "icons/icon16.png",
diff --git a/popup.html b/popup.html
index 264037a..9848f97 100644
--- a/popup.html
+++ b/popup.html
@@ -7,7 +7,7 @@
   <body>
     <!-- Main filter view -->
     <div id="filterView" class="view hidden">
-      <button id="addFilterBtn" class="add-filter-btn">Add New Filter</button>
+      <button id="addFilterBtn" class="add-filter-btn" data-i18n="addFilterButton">Add New Filter</button>
 
       <div id="filterList" class="filter-list">
         <!-- Filters will be populated here by JavaScript -->
@@ -16,16 +16,17 @@
 
     <!-- Add new filter view -->
     <div id="addFilterView" class="view hidden add-filter-view">
-      <button id="backBtn" class="back-btn">←</button>
+      <button id="backBtn" class="back-btn" data-i18n="backButton">←</button>
 
       <div class="add-filter-form">
         <input
           type="text"
           id="filterInput"
+          data-i18n-placeholder="filterInputPlaceholder"
           placeholder="Enter filter keyword..."
           class="filter-input"
         />
-        <button id="confirmBtn" class="confirm-btn" disabled="true">
+        <button id="confirmBtn" class="confirm-btn" disabled="true" data-i18n="confirmButton">
           Confirm
         </button>
       </div>
diff --git a/popup.js b/popup.js
index 2dfc249..e6745a0 100644
--- a/popup.js
+++ b/popup.js
@@ -55,8 +55,32 @@ function shouldClearActiveFilter(filterToRemove, currentActiveFilter) {
   return currentActiveFilter === filterToRemove;
 }
 
+// Initialize i18n for all elements with data-i18n attribute
+function initializeI18n() {
+  // Handle text content localization
+  document.querySelectorAll('[data-i18n]').forEach((element) => {
+    const key = element.getAttribute('data-i18n');
+    const message = chrome.i18n.getMessage(key);
+    if (message) {
+      element.textContent = message;
+    }
+  });
+
+  // Handle placeholder localization
+  document.querySelectorAll('[data-i18n-placeholder]').forEach((element) => {
+    const key = element.getAttribute('data-i18n-placeholder');
+    const message = chrome.i18n.getMessage(key);
+    if (message) {
+      element.placeholder = message;
+    }
+  });
+}
+
 // UI Controller
 document.addEventListener('DOMContentLoaded', async function () {
+  // Initialize i18n
+  initializeI18n();
+
   // DOM elements
   const filterView = document.getElementById('filterView');
   const addFilterView = document.getElementById('addFilterView');